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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