steve05: Where we live it was a mild winter, and the lowest was 10FH. I used the engine block heater twice just to see how it did. The ONLY thing I noticed was a little smoother starting. So I just did not use it any more. It got down to 10FH several more times and it started just fine, just not quite as smooth at first. I am not at all sure that re start remark is really good, I don't believe you need to do that. Did you find the cord for the heater ok?
The sales guy at the stealership told me to cycle the key/glowplugs a couple times when it was real cold. I never did. Mine has started at -10F without plugged in, with some power service in it, and at 10,200 feet above sea level. That was all before the latest flash that keeps the glow plugs on a little longer. No worries here.
Siberia, my post was half a comment of disgust about the oil in the intercooler/charged air cooler-whichever term one is use to using.
I was wanting to see if a combustion engineer would speak up. My gassers seem to run great on cool slightly humid nights. I don't know about diesel combustion. Do diesels run better(produce less emissions) in the desert with no humidity? How cool/cold would be ideal for the intake? An evaporator in the cooler could chill the air (and would condense water vapor needing to be released?) But cool air and gunk from a poorly designed ccv won't mix.
There is the upward slope to the hose as well. If the oil is in a mist, which it must be, then it would have a tendancy to collect on the downhill side of the hose and run back into the intercooler. Not an engineer, just an observance. What is your engine oil level? If it is up to the full mark, it is about 1/2 qt. too full.
Gassers like cool humid nights because the moisture in the air helps the gasoline in the mixture burn more evenly and with more power. I was in the USAF and flew on C-123 aircraft. They had huge P&W 18 cylinder engines with water injection. I asked the pilot to do a takeoff with and without the water injection turned on. With the water on, there was a small but noticeable improvement in performance.
As for diesels, I know they like warm to hot weather better than cold weather. On Friday, my CRD will have been with me for one year. I have driven it in all sorts of conditions and have not noticed any performance differences once warmed up. If the air coming into the intake is too cool, you could lose performance because you need heat to ignite the fuel and if you need more energy to heat the air in the combustion chamber of a diesel, then you will lose efficiency/performance. The addition of moisture has no real impact on a diesel's performance as it does on gassers, but I could be wrong. The injection of propane into the air mixture of a diesel makes for very interesting horsepower improvements.
The oil level being off has been talked to death over on LOST, but I do know that mine is off a bit. It just sounds to reason, that if it were too full, that oil is going to go somewhere. We shall see.
Thanks for the tip Europasusan. I will check the motor mounts this weekend. It could be something like a motor mount making the noise and I just happen to have a bad ball joint, too.
Hey Farout! Found the heater cord & re-routed it today, Thanks! The most remarked at thing when I pop the hood for my diesel-truck-driving friends is the Optima battery from the factory. I admit I was also impressed - and baffled: all other diesels I had seen had twin batteries (I've never seen under the hood of a diesel VW). This is my 4th Jeep: '78 CJ5 (304), '79 CJ7 (304), and my most recent '94 Cherokee Country (eye6). I've been going "green" for a few years - solar panels, a wind turbine, flourecent lights, plugs strips for everything in the house with a remote, etc - and had been eagerly researching biodiesel. I was actually about to convert the Cherokee to propane. Imagine my excitement last fall when I heard JEEP had a diesel. (Word of mouth, sadly, then to the website - is it just me, or has there been ZERO advertising for the CRD?) Now I have one and haven't yet put any bio in, but it is a matter of time. It purrs rather nicely compared to those 1-ton dodges and fords and at highway speeds I can't tell that it's a diesel by the sound of it. Added a bunch of factory aftermarket stuff this week - the cargo liner, the cargo cover, a cool "Jeep" spare tire cover, the carbon fibre dash applique, bike carriers, window vent shades, the "wetsuit" seat covers, and bought the kayak carrier as well - just need a kayak. I'm told by the dealer here that June 1st sees the release of a factory iPod adapter - SWEET! When it is available I'm going to get that and the factory sub-woofer, possbly the factory remote start (another key fob - bummer!) I feel like a kid all over again - in my forties! :shades:
Farmer52: My CRD came with an RB1 radio. I added the factory SIRIUS receiver not long ago. It displays the channel number, channel name, song title, and artist. It needed an adapter kit for about $30 (not sure why). AutoTruckToys.com sold me the receiver kit, adapter kit, and lifetime subscription to SIRIUS (no monthly pymts) for around $470. Thought that was pretty good considering SIRIUS wants $500 just for the lifetime subscription.
bvcrd - I admit, you are correct - I just sold my souped-up little red sports car today, but I bought a harley last month. and - hey, suddenly I need a beer....
Winter2 What about flying in a caribou or does that show my age.
I don't know what the air temp is before and after the cac or how much cooling is needed or settled for in cac design. But with contamination from ccv oil (none should be the acceptable limit), the differential has to be diminished and may be a performance issue on hot summer southern days. I am afraid to go to 15w40 like you. I should have gone to 5w40 sooner like those of you with prior diesel experience.
The a/c idea that popped into my mind as I was posting awhile back has stuck with me. Could any summer advantage be gained by using some of the refrigerant and a small evaporator on the top of a cac to (1)reduce the temp or (2)reduce the temp and dehumidify the air to the intake. Thermodynamics and diesel design is not cup of tea/coffee.
Going on 15 months soon. Not looking forward to second differentials grease change-12,500 mile intervals seems like a money raiser for DC dealers for owners like us who seldom even seen rain let alone the rubicon. Fuel filter change was a non issue.
About the advertising... I saw ads put in the Windsor star,and Toronto SUN..
In Canada they are starting to advertise the Diesel option in the liberty. Well it's about time !...
Now that gas is at $5/gal and diesel at $4/gal,we are seeing some good marketing on DCX 's part.
They showed a discount price for the "SPORT Liberty diesel" Listed at $26K Ca,not bad considering Toyota RAV 4 is going for $33K, 24-28mpg,but no towing capacity. and The Liberty with a 5000 lbs towing capacity, 26-33mpg, and listed in the "Energy guide" "Recommended Buy" as an econmical SUV.
YaaaH..Hooo ! ... I hope The U.S contingent does the same !.. Work Hard Play hard !. Lightnin...
eebro, The emissions control cycle of the engine controller is only activated when the pedal is marginally depressed. I strongly believe this shudder happens during the end of the emission limitation duty cycle. I was able to correct this on my truck because I don't a closed loop.
What about flying in a caribou or does that show my age If you import a second hand euro-2003 you will be spoiled and not understood nor credible to others!
At 22 F ambient temp, Air Inlet Temp (AIT) on a CRD runs around 90 F at 65 MPH (maybe okay). At 85 F ambient temp, AIT runs around 150 F at the same speed. The temperature is measured after the intercooler in the intake manifold. What is it when ambient temp is 105 F and the water temp climbs a little? My CRD runs 163 F water temp at 65 MPH and 85 F (argument for thinner oil?)
The intercooler cools the intake air only for the EGR gas to heat it up again. Do we need another intercooler just for the EGR gasses - at least for summer time?
The problem with all this is the ECU would have to be reprogrammed for different timing and fuel contour. And, the water temperature should probably be 190 F, maybe, not 163 F.
In the 70's if you disabled an EGR valve on a gasser you had to alter the timing and mixture or the gas mileage actually went down.
siberia, I read in the technical litterature that the fuel temperature is the critical issue and this is why we have a fuel heater. It seems diesel fuel is difficult to inject in very accurate quantities when it is below a certain range of temperature. There is greater latitude for compressed air temperature going in the cylinder since it refers to Kelvin degrees and pressure ratio.
Just got on to catch up on posts and thought I'd add my new learnings. The other day I drove the jeep into work myself - (hubbie usually drives). I tried a few of the tricks I've read here, since I had extra time. 1) I did not turn O/D off at any time. No shudder in the 40-50 mph range w O/D on this way. 2) I decelerated in cruise down to 1800 rpms and watched the mpg go up considerably. 3) I left the jeep in cruise going into the city in the 50 mpg zone - where we feel the jeep shudder routinely. This one concerns me the most since it's about a 1% downgrade and we have O/D ON. BUT... with the cruise control on it didn't shudder once!
So - first time ever I didn't experience the shudder any time during my commute! Makes what Caribou1 noted make some sense. Guess I'll be checking into this more. I can't tell you how pleased I was to have a ride without shudder! Michelle
I have been following and posting on this board since last summer before I bought my 05 CRD with a July build date. What confuses me is the erratic MPG reporting I see on this board. The best mileage I have ever experienced with my CRD is just shy of 28 MPG and that was on the very first 125 mile trip. I immediately fueled it up at a station within site of the interstate so I had no around town driving. I now have 15,000 miles on my CRD and have calculated the MPG for every tankfull since I bought it. I usually fill up when I get down to 3-4 gallons left in the tank and I divide the miles driven by the number of gallons pumped. I usually get about 21-22.5 mpg with my best (since the first trip) being around 25 for 90% highway driving. I know what you are going to say, how you drive it makes a difference. Other than blowing it's nose once a day or so, I drive very conservatively with MPG in mind.
So here is my question? Those of you posting the 27-33 mpg on this board, are you actually getting this kind of mileage of a complete tankful as calculated by my method or are you simply looking at your onboard computer and taking the higest number for a specified highway drive rather than a whole tank. I have no faith in the on board computer when it comes to computing real MPG. If anyone is getting these higher MPG numbers on complete tankfulls of fuel as calculated by hand, please let us know and tell us how you calculated and how you drove the vehicle. I personally have a hard time believing these vehicles get 30+ mpg for a complete tank when driven normally and computed this way. Computer mileage in my book doesn't count.
No man, we don't have no stinking on board computer man. I have never driven the tank that low before, but mine is calculated after say 2-300 mile trips. Doesn't really matter though, it would get the same if I drove 500 or 200 mile trips. Still get 26-27 ALL THE TIME and as much as 32 mpg SOME OF THE TIME. Only thing I can say is it must be making a difference HOW you get up to cruising speed. I get there as gently as I can, and once there, drive 62 in a 65.
I'll tell you what, at least with Chrysler, Dieter Zetsche is sounding like his is going to be behind diesel vehicles like the Liberty and the GC(right?) coming with diesel engines in them. If he can stay this course and not be swayed from it, he may succeed in America and we'll see more diesels come to the US roads. So far, My Liberty is doing well and I've been getting around 23 MPG going to work, running around locally, etc. and 27 on trips.
I have a May 05 build date Limited . I have been keeping track of my fuel economy since 6.29.05 using the trip miles divided by gallons to fill method . My worst rating was 20.79 mpg in mid December . This was with 10 ply studded tires running in full time 4X4 and very cold temperatures. Best fuel economy was 33.21 in mid September with stock tires on a long highway trip . I went 605.4 miles on that tank . My Liberty has 18,600 miles now and I love it . I had shuddering problems early on that I determined was caused by poor quality fuel .
I just happen to like the brand of tire . They are Nokian Hakkapeliitta LT's . They ride almost as smooth as the stock tires and I am much less concerned about punctures .
Thank you very much. Computers again. It's a shame because the a/c lines are in a great location. Maybe some smart engineer can use this idea.
I'm sure a lot of my 0w40 has turned to a nice gooey coating in the cac tubes. I can't wait for summer number two (got but didn't ask for the temp guage recalibration).
Last week I bought some diesel fuel at an independent truck stop in Gap, PA. I usually use Sunoco's Premium Diesel. About 15 miles after fill-up under light acceleration it gave off much black smoke and less power. About 100 miles later after passing a car I finally experienced the bucking most of you are complaining about. On my next fill up I went back to the Sunoco Diesel and everything is back to normal. No matter what I do I can't reproduce the bucking. The last time I ever experienced anything like this was when the vehicles at work were having injector response time issues. Too the extent of being a fleet failure. After a few weeks we had our fuel tested and found bacteria growing in our 20,000 gallons underground tanks. No filter in the world will solve this problem. So I agree with chugga. Poor quality fuel must be avoided. Also keep in mind that the big over the road diesel trucks run hotter and are much more tolerant to cheap, poor quality fuels. Some can run on almost straight engine oil. Plus I don't have a fuel mileage computer on mine. I drive over 600 miles a week and average 26.35 MPGs. Mostly highway at 65 to 75 MPH.
Yes, I would have enjoyed a a less restricted 2.5 crd years ago. I believe it is easier to export. Caribou - an army fixed wing plane, you swear you could walk faster than you were flying.
We used to get a boo in our Alaskan village about 3 times a year. It was mainly used to carry freight. I liked the way the rear came open. It did fly low and slow. Looked like you could knock it out of the sky with a sling shot.
I forgot to add when I posted this message that I also add diesel fuel additive to raise the cetane level and help with MPG. I also run my tires at 38 psi to improve economy. If you guys are really getting the higher mileage then there must be something wrong with my jeep. I don't think it is the way that I drive it. If I accelerate any slower I'm gonna get run over. Granted, I can't bring myself to drive 62 mph on the highway but I genrally don't exceed 70 and try to shoot for 65-70 as traffic allows. I just find it so hard to believe that you are getting an extra 100 miles out of a tank of fuel..... I'm doing something wrong. :confuse:
Then it's your speed. When my wife drives it, she goes 67 in a 65 and 55 in a 50. I have noticed the mpg drops down to 24 during these times. The rpms need to be no more than 1700 to get these numbers. Try it. Fill it up and make yourself drive like this and report back to me.
Here's what works best for me :Stock tires at 36 psi, no fuel additives of any kind , set cruise to 60 then back down using the decel button to about 58. If I know the road if flat for a long time I will set my speed to 1650 rpm's . If there are hills then I'll set the speed to 1800 rpm's .
I find myself in your camp. I've had mine since August of '05 and have been getting anywhere from 19.5 to 21.5 in mixed city/highway driving. If I get it up to 50 mph on a level road, set the cruise, and do not accelerate or decelerate for 10 miles or so, I'll see 25.5 to 27. I also stand the very real chance of being run over by some little blue-haired lady in a Yugo! :confuse:
I have read about other tire sizes for the CRD but they all are wider than stock. Does anyone have any experience with larger tires in order to get better ground clearance. I'm not ready to go lifted yet but the stock tires seem to have a lot of room in the wheel wells. I'm thinking 235x85-16 just might fit. Anyone tried this?
I hate to be the realist but driving at 58 mph on a 65 mph east coast interstate is extremely dangerous. Most vehicles travel at 75 and quite a few at 80 - 85 mph. To me "real" mpg should be calculated at real highway speeds. Driving a vehicle as slow as mechanically possible in order to push MPG isn't a fair statistic for real world purposes. When I compare this vehicle to other makes and models out there, I know they aren't scientifically figuring out the "sweet spot" and driving at that speed regardless of traffic, speed limits, or safety. To me, the MPG at 65-70 mph is the "real world" MPG for this vehicle. I think if that was communicated then the expectations for this vehicle would be more realistic. If anyone out there is reading this and considering buying a CRD because you think it will get 30 MPG on the highway, you will most likely be disappointed. Expect 22-25 on the highway at 65- 70 mph (depending on outside air temp, etc) 20 -22 mpg rural driving' and 18-21 mixed city/ all around driving and you will probably be alot happier. Overall I like my CRD but I do find myself lusting after a truely economical vehicle like the VW TDI - if they only could tow or come in AWD! Don't get me wrong, I'm not a CRD basher - they are good vehicles but they are quirky and aren't for everyone. Probably the biggest bummer is dirty, smelly pump handles at fuel stations and the "cool down" before you can shut the engine off. People at work will really think you are strange when they see you sitting in your CRD waiting 1-3 minutes for the turbo to cool down before you walk into the building day after day! That being said, I still like mine!
Siberia: I had a 2002 Dakota quad cab, and in 92,000 miles DCX replaced both upper and lower ball joints, left and right sides 4 times and when I got rid of it it needed to have them replaced all over again. Every time I asked them to use Moog, but no,...had to be genuine DCX part. Considering that the ball joints came with the control arms, this had to be about $300. a side. If my math is right this means DCX spent about $2,400. replacing parts that were ill conceived. Every ball joint was dry no lubercation! This problem popped its ugly head at about 12,000 miles. The road we live on is a steep rugged rocky gravel road. So the Jeep so far has held up very well. But this time if I have to replace them under warranty I will ask if I can pay for the parts and get Moog. They are about 20% more in price, but you get a zerk fitting. That's what is the real problem, I think anyway.
steve05: Hey guy, forties is still a young buck! I am in my early sixties, and still get a kick out of owning something that's cool to talk about and better to drive. We too have made a big attempt to become more "green". Flourecent lights, and we built our own house on 3 acres of land near the lake. Nice place to retire, but not very good for a family unless hubby has a skilled trade. Land is very reasonable and electricity is one of the most economic in the US. We garden and we have had our own chickens until recently. I think it responsible to be prudent with energy. We have no car or Jeep that does not have a 4 cyl engine. We have the cargo organizer and it came with the Jeep and cost $250. I was not happy about having to buy something I did not think we would use. However, we would be lost without it! It's one of the best $250. buys we have gotten in a long time. I had the mud flaps put on and the spare tire cover put on and we dumped the ST tires with in the first 300 miles. We put GoodYear Wrangler Silent Armor 245 70 16 T on and they are really great. First set of Good Year tires I have every bought after I got a new vehicle. Hope you enjoy your Jeep as much as we do ours.
The radiator shop that freightliner sent me to called the intercooler, a cac(charged air cooler). I guess I need to say intercooler and noticed that I said cac tubes when I meant the passages in the intercooler. It seems you have more resources than me, and your questions seem more than rhetorical.
Thinner oil, maybe but I've now had all the thin oil I want in a closed diesel turbo system. I believed the 5w20 in our ford was basically additional coolant as much as a lubricant.
If I don't get an old navy ccv soon and cleanout our entire system, we will find out this summer. Hot temps, an intercooler underperforming from ccv buildup, and texas crap diesel.
Water temperature at 190 F. I was glad when it got cool that the viscous heater did a fine job. Is this a thermostat rated at too low of a temp issue or that diesels run cool compared to gassers. If water temp is needed-engage the water heater. Does this mean if the intake is free from junk, AIT is chilled, and the block is kept warm - we can get the best of all worlds and burn cleaner to boot?
New2diese: I too have never achieved anything close to 30 mpg. I really thought 24 would be a good average to count on, but that is not the reality. I don't have the on board computer either. I use the exact method as you in finding the true mpg. I do it for long periods and then average, say ten or so fillings. I typically get 22 mpg US. I have once in a while got 23.5, but that's not often. I drive for the most part in hills and not straight roads. I have tried Cetane boosters, anti-gell/Cetane boosters and they did nothing noticeable. But, last week I had the latest tsb done. Two were done and I have done the others as they came out. But these last two made a big difference. We got 27.6 mpg. I don't know why or how but we did. This last tank we went 263 miles on 10 gal. Perhaps it's the tsb's that were done, or maybe it's because we have just turned almost 13,000 miles. Perhaps its that winter fuel has changed over to the summer fuel. I also had to add a quart od oil and put 5-40 Shell Rotella, which I am going to use from now on. I also am going to change the air filter soon as it looks like oil is dripping from the right back side of the air filter. I have no idea why either. When I read of others getting 30 mpg, I have to remember I have not gone on a long trip to see what that would bring. And I wonder if the wider tires might have an effect on mpg. However 245 70 16 isn't that much wider, I don't think. At any rate 22 mpg is a lot better than 14 to 16.5 on our 05 Limited Liberty we traded in on the CRD. The only thing I am wondering is with DCX not making a diesel for 07 and maybe not until 08, will this make the value of the CRD drop like a lead rock? I do feel we are a test market for DCX and we paid a lot to test DCX's test diesels. I think they should give us something for our paying to be a part of their testing. We really like the CRD and would do it all over, but I sure wish diesel would be less cost than un. reg. Here diesel is 10 cents higher, $2.80. Well at least we don't have to get fuel on odd or even days as we did in 1974. That being said, I still like ours too.
I donno, Farout. I'm with you, I don't understand DCX's thinking. DCX must have made a huge number of extra ball joints. Maybe some accountants are doing the math and somehow they think it's cheaper to use the parts they have rather than substituting good parts. Probably a couple of statisticians are involved too, calculating the probability of failure. My biggest concern is the ball joint separations that have occurred.
Recent trip: 361 miles used 11.45 gals = 31.5 mpg / 241 miles speed limit 70 drove 65 / 70 miles speed limit 60 drove 65 / 50 miles speed limit 55 drove 45 to 60 / Cross tail wind 7-10 mph, temp 60 F / 1 pit stop / trip computer read 27.7 mpg.
Return trip: 396 miles using 15.61 gals = 25.4 mpg / 75 miles speed limit 70 drove 70 / 321 miles speed limit 60 drove 55 – 65 / Cross head wind 30 mph, temp 50, light to moderate rain / 4 pit stops (1 to buy jerky) / played with trip computer.
Driving style on 31.5 mpg trip was: set the cruise and forget it / no defense of lane / when ****wads make stupid moves around you no getting mad and hitting the throttle / no blowing it’s nose / no accelerating around a truck to beat the left lane traffic / when the choice is hitting the throttle or slowing down, slow down / slow acceleration on onramps / use neutral and coast when appropriate – neutral at long stoplights / throw in 1 panic stop - missed turn - off road down bank through ditch then up to right road.
Driving style on 25.4 mpg return trip was: violate about half of the above rules, make a couple of wrong turns on new route and argue with the wife a little.
According to the following seemingly knowledgeable web site, "cool down" is not required in modern turbo diesels, especially with synthetic oils. There are also some other interesting points at this site.
Comments
Farout
Actually, the U.S. imports more oil from Canada than from any other country.
tidester, host
I was wanting to see if a combustion engineer would speak up. My gassers seem to run great on cool slightly humid nights. I don't know about diesel combustion. Do diesels run better(produce less emissions) in the desert with no humidity? How cool/cold would be ideal for the intake? An evaporator in the cooler could chill the air (and would condense water vapor needing to be released?)
But cool air and gunk from a poorly designed ccv won't mix.
Gassers like cool humid nights because the moisture in the air helps the gasoline in the mixture burn more evenly and with more power. I was in the USAF and flew on C-123 aircraft. They had huge P&W 18 cylinder engines with water injection. I asked the pilot to do a takeoff with and without the water injection turned on. With the water on, there was a small but noticeable improvement in performance.
As for diesels, I know they like warm to hot weather better than cold weather. On Friday, my CRD will have been with me for one year. I have driven it in all sorts of conditions and have not noticed any performance differences once warmed up. If the air coming into the intake is too cool, you could lose performance because you need heat to ignite the fuel and if you need more energy to heat the air in the combustion chamber of a diesel, then you will lose efficiency/performance. The addition of moisture has no real impact on a diesel's performance as it does on gassers, but I could be wrong. The injection of propane into the air mixture of a diesel makes for very interesting horsepower improvements.
W
Thanks, Farout.
Love the CRD and have really enjoyed the SIRIUS!
What about flying in a caribou or does that show my age.
I don't know what the air temp is before and after the cac or how much cooling is needed or settled for in cac design. But with contamination from ccv oil (none should be the acceptable limit), the differential has to be diminished and may be a performance issue on hot summer southern days. I am afraid to go to 15w40 like you. I should have gone to 5w40 sooner like those of you with prior diesel experience.
The a/c idea that popped into my mind as I was posting awhile back has stuck with me. Could any summer advantage be gained by using some of the refrigerant and a small evaporator on the top of a cac to (1)reduce the temp or (2)reduce the temp and dehumidify the air to the intake.
Thermodynamics and diesel design is not cup of tea/coffee.
Going on 15 months soon. Not looking forward to second differentials grease change-12,500 mile intervals seems like a money raiser for DC dealers for owners like us who seldom even seen rain let alone the rubicon. Fuel filter change was a non issue.
About the advertising...
I saw ads put in the Windsor star,and Toronto SUN..
In Canada they are starting to advertise the Diesel option in the liberty.
Well it's about time !...
Now that gas is at $5/gal and diesel at $4/gal,we are seeing some good marketing on DCX 's part.
They showed a discount price for the "SPORT Liberty diesel"
Listed at $26K Ca,not bad considering Toyota RAV 4 is going for $33K, 24-28mpg,but no towing capacity.
and The Liberty with a 5000 lbs towing capacity,
26-33mpg,
and listed in the "Energy guide" "Recommended Buy" as an econmical SUV.
YaaaH..Hooo ! ...
I hope The U.S contingent does the same !..
Work Hard Play hard !.
Lightnin...
The emissions control cycle of the engine controller is only activated when the pedal is marginally depressed. I strongly believe this shudder happens during the end of the emission limitation duty cycle. I was able to correct this on my truck because I don't a closed loop.
If you import a second hand euro-2003 you will be spoiled and not understood nor credible to others!
Once again, I think you are on to something.
At 22 F ambient temp, Air Inlet Temp (AIT) on a CRD runs around 90 F at 65 MPH (maybe okay). At 85 F ambient temp, AIT runs around 150 F at the same speed. The temperature is measured after the intercooler in the intake manifold. What is it when ambient temp is 105 F and the water temp climbs a little? My CRD runs 163 F water temp at 65 MPH and 85 F (argument for thinner oil?)
The intercooler cools the intake air only for the EGR gas to heat it up again. Do we need another intercooler just for the EGR gasses - at least for summer time?
The problem with all this is the ECU would have to be reprogrammed for different timing and fuel contour. And, the water temperature should probably be 190 F, maybe, not 163 F.
In the 70's if you disabled an EGR valve on a gasser you had to alter the timing and mixture or the gas mileage actually went down.
I read in the technical litterature that the fuel temperature is the critical issue and this is why we have a fuel heater. It seems diesel fuel is difficult to inject in very accurate quantities when it is below a certain range of temperature. There is greater latitude for compressed air temperature going in the cylinder since it refers to Kelvin degrees and pressure ratio.
1) I did not turn O/D off at any time. No shudder in the 40-50 mph range w O/D on this way.
2) I decelerated in cruise down to 1800 rpms and watched the mpg go up considerably.
3) I left the jeep in cruise going into the city in the 50 mpg zone - where we feel the jeep shudder routinely. This one concerns me the most since it's about a 1% downgrade and we have O/D ON. BUT... with the cruise control on it didn't shudder once!
So - first time ever I didn't experience the shudder any time during my commute!
Makes what Caribou1 noted make some sense. Guess I'll be checking into this more.
I can't tell you how pleased I was to have a ride without shudder!
Michelle
So here is my question? Those of you posting the 27-33 mpg on this board, are you actually getting this kind of mileage of a complete tankful as calculated by my method or are you simply looking at your onboard computer and taking the higest number for a specified highway drive rather than a whole tank. I have no faith in the on board computer when it comes to computing real MPG. If anyone is getting these higher MPG numbers on complete tankfulls of fuel as calculated by hand, please let us know and tell us how you calculated and how you drove the vehicle. I personally have a hard time believing these vehicles get 30+ mpg for a complete tank when driven normally and computed this way. Computer mileage in my book doesn't count.
You are opening a breach
Lots of folks with various cars have compared their computer numbers with the manual way you and I do it and they report no significant differences.
Steve, Host
I'm sure a lot of my 0w40 has turned to a nice gooey coating in the cac tubes. I can't wait for summer number two (got but didn't ask for the temp guage recalibration).
Caribou - an army fixed wing plane, you swear you could walk faster than you were flying.
CRD - a little high.
If you guys are really getting the higher mileage then there must be something wrong with my jeep. I don't think it is the way that I drive it. If I accelerate any slower I'm gonna get run over. Granted, I can't bring myself to drive 62 mph on the highway but I genrally don't exceed 70 and try to shoot for 65-70 as traffic allows. I just find it so hard to believe that you are getting an extra 100 miles out of a tank of fuel..... I'm doing something wrong.
:confuse:
I find myself in your camp. I've had mine since August of '05 and have been getting anywhere from 19.5 to 21.5 in mixed city/highway driving. If I get it up to 50 mph on a level road, set the cruise, and do not accelerate or decelerate for 10 miles or so, I'll see 25.5 to 27. I also stand the very real chance of being run over by some little blue-haired lady in a Yugo! :confuse:
This problem popped its ugly head at about 12,000 miles. The road we live on is a steep rugged rocky gravel road. So the Jeep so far has held up very well. But this time if I have to replace them under warranty I will ask if I can pay for the parts and get Moog. They are about 20% more in price, but you get a zerk fitting. That's what is the real problem, I think anyway.
Farout
We have the cargo organizer and it came with the Jeep and cost $250. I was not happy about having to buy something I did not think we would use. However, we would be lost without it! It's one of the best $250. buys we have gotten in a long time. I had the mud flaps put on and the spare tire cover put on and we dumped the ST tires with in the first 300 miles. We put GoodYear Wrangler Silent Armor 245 70 16 T on and they are really great. First set of Good Year tires I have every bought after I got a new vehicle. Hope you enjoy your Jeep as much as we do ours.
Farout
Thinner oil, maybe but I've now had all the thin oil I want in a closed diesel turbo system. I believed the 5w20 in our ford was basically additional coolant as much as a lubricant.
If I don't get an old navy ccv soon and cleanout our entire system, we will find out this summer. Hot temps, an intercooler underperforming from ccv buildup, and texas crap diesel.
Water temperature at 190 F. I was glad when it got cool that the viscous heater did a fine job. Is this a thermostat rated at too low of a temp issue or that diesels run cool compared to gassers. If water temp is needed-engage the water heater. Does this mean if the intake is free from junk, AIT is chilled, and the block is kept warm - we can get the best of all worlds and burn cleaner to boot?
I also am going to change the air filter soon as it looks like oil is dripping from the right back side of the air filter. I have no idea why either.
When I read of others getting 30 mpg, I have to remember I have not gone on a long trip to see what that would bring. And I wonder if the wider tires might have an effect on mpg. However 245 70 16 isn't that much wider, I don't think. At any rate 22 mpg is a lot better than 14 to 16.5 on our 05 Limited Liberty we traded in on the CRD.
The only thing I am wondering is with DCX not making a diesel for 07 and maybe not until 08, will this make the value of the CRD drop like a lead rock? I do feel we are a test market for DCX and we paid a lot to test DCX's test diesels. I think they should give us something for our paying to be a part of their testing. We really like the CRD and would do it all over, but I sure wish diesel would be less cost than un. reg. Here diesel is 10 cents higher, $2.80. Well at least we don't have to get fuel on odd or even days as we did in 1974. That being said, I still like ours too.
Farout
Recent trip: 361 miles used 11.45 gals = 31.5 mpg / 241 miles speed limit 70 drove 65 / 70 miles speed limit 60 drove 65 / 50 miles speed limit 55 drove 45 to 60 / Cross tail wind 7-10 mph, temp 60 F / 1 pit stop / trip computer read 27.7 mpg.
Return trip: 396 miles using 15.61 gals = 25.4 mpg / 75 miles speed limit 70 drove 70 / 321 miles speed limit 60 drove 55 – 65 / Cross head wind 30 mph, temp 50, light to moderate rain / 4 pit stops (1 to buy jerky) / played with trip computer.
Driving style on 31.5 mpg trip was: set the cruise and forget it / no defense of lane / when ****wads make stupid moves around you no getting mad and hitting the throttle / no blowing it’s nose / no accelerating around a truck to beat the left lane traffic / when the choice is hitting the throttle or slowing down, slow down / slow acceleration on onramps / use neutral and coast when appropriate – neutral at long stoplights / throw in 1 panic stop - missed turn - off road down bank through ditch then up to right road.
Driving style on 25.4 mpg return trip was: violate about half of the above rules, make a couple of wrong turns on new route and argue with the wife a little.
http://www.bankspower.com/tech_TD-fact-Fiction.cfm