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Gas Mileage

BobbdBobbd Posts: 1
I have a 1993 Ford F-150 Supercab. The best
vehicle I've ever owned. It is comfortable, goes
in the snow, hauls with no problem, and I think it
looks great. Truck owners, I'm sure don't expect
to get good gas mileage, but 10 mpg is getting old.
I justify it by realizing it is a heavy truck,
the 302 isn't the best truck motor, and there is a
price to pay for driving something like that. I
have always done more than the expected prevenative
maintenance and was just curious if anyone else
had better luck with economy than I am having. The
last set of plugs I put in are platinum (no
improvement); if anything it is worse.
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Comments

  • kirkpamakirkpama Posts: 64
    Brutus,

    I have a 90 F250 with the 302 and I have been getting 10 to 11 mpg from day one. I have 56,000 miles on it now. I believe that this engine is too small for this size truck and it has to work harder and the mpg suffers. Just a guess. I can't wait until my V-10 arrives.
  • BrutusBrutus Posts: 1,113
    I had a feeling that might be it. It's one of those things that has never been mentioned in some of the other topic areas when we've talked about getting a big enough engine and suspension for the job you plan to do. The main arguments for the bigger engine have been that the smaller engine will work harder and may not last as long. It never really occured to me that it might not get much better gas mileage from the start. If that's the case, I'm wondering if the people who are getting the new F-150s with the smaller V-8 will encounter the same thing? I'm looking forward to the V-10 as well, although I can't complain about the 351.
  • thegoinkerthegoinker Posts: 8
      I just turned 2K on my 3.9L V6 Dakota short bed-(Auto). In town, I have calculated 13.5 mpg. Is this figure in line with what this engine should be performing? I have not been on a road trip so far, so no mpg for hyway. The factory sticker in the window had it at 16city/21hwy mpg. I do no towing or hauling, moderate idling and am mostly on side streets for delivering. Also, while sitting at a stop light, it stinks to high heaven. (that catalytic converter stink) Being that the truck was built in Warren, Michigan would it have been tuned for a higher altitude than here in West Central Florida? I just do not know how these modern "brain" systems work as far as what is "normal" performance. Makes one long for the old time engines one could tune-up with a plug wrench, matchbook and a screwdriver!!
  • BrutusBrutus Posts: 1,113
    I think it will be hard to tell if the gas mileage is getting close to the specs until you get it out on a highway trip for a few hundred miles. City mileage can vary significantly based on driving conditions. Highway mileage is more uniform, especially if you have cruise control.
  • AirCatAirCat Posts: 16
    I am currently towing my boat with a Blazer with a 350 in it and my father is towing his boat with a 96 CHEVK2500 PU with a 350, both of us get 11 mpg when towing but I get 15 to his 14 highway when were not towing, I expect to beat the socks off of him towing a heavier load when my new V10 finally arrives. I think being just a little underpowered hurts milage a lot.
  • reset9reset9 Posts: 7
    #4
    "...and am mostly on side streets for delivering."
    Stop and go driving reduces mileage.
  • cdeancdean Posts: 1,110
    Aircat

    You expect to get better mileage with a V10? that v10 will probably get 11 or 12 not pulling. You've got to realize that due to the torque curves of gas motors, they are not going to get good mileage pulling. One reason you get such a drop off is because of your gear ratio. I suspect you have a 3.42 rear end from your mileage. That is a highway rearend, not towing.
    The engine is working pretty hard, no matter what you pull. I have a chev 350 in a '94 pickup with a 3.42 gear. i get 18-19 highway, but pulling around my 3500 lb boat, i only get 10-11. I could get a 3.73, like in my mom's suburban, and i would get about 16 highway, and 13 pulling. so thats the trade off. if you had a lower gear, you would get slightly less driving mileage, but better pulling mileage. it all depends on what the majority of your driving is. By getting v10, you will have great power, but bad gas mileage all the way around (compared to your 350), probably less than 10 when you pull, depending on your gear ratio.

    i will say one thing about new engines from ford and chevy (i haven't seen the torque curves from dodge) and that is they have almost 90% of their torque at 2000rpms, which is kinda the same property that makes diesels great pullers. So i might be in for a surprise when you write in later and report on the performance. but gas motors are almost at the end of their refinement. In non-engineering terms, they are pretty much as good as their ever going to get. so don't expect to beat the pants of anybody in a mileage contest with a V10.

    cdean
  • AirCatAirCat Posts: 16
    The inventory co next door to where I work have the same Ford V10 in their 15 pass van. They tow a trailer loaded with their equip. and claim to get over 15 mpg with it., I really believe underpowering is as bad for milage as overpowering or worse. You dont have to mash the pedal all day to get there with a bigger motor.
  • rite3rite3 Posts: 69
    I have heard this kind of mileage with the V10 also. The guys who have motorhomes built on the van chassis with the 6.8 say they are getting 13. I can only imagine what the pickups will get, I hope its all true. I know my 460 dousnt get far enough from the pump to get that mpg.
  • RoclesRocles Posts: 985
    Don't subscribe to the attitude that gas engines have reached their peak in refinement. The last time, Iaccoa cried that Americans could only build fat monsters and wouldn't be able to build a small car. I think mileage will improve when the industry is forced to by market changes.
    Back to actual topic:Bought our 12th truck and I bought a "topper".Roofing lingo for a crew truck of three guys just doing easy jobs like shingling over existing roofs. We only needed a light truck for these quick jobs so we got an F-150 with the 4.2 six. The plan is to use this truck for estimates and lots of driving without load. Waiting for mileage results.
    Funny though, we have three 95 Chevy's bought at the same time(same engines) and two get 14-16 mpg whereas the other gets 11-13. I never could explain this especially after ruling out some clowns that work for us who drive them. All three get routine maintenance at the same time. I would love insight to this situation.
  • cdeancdean Posts: 1,110
    Rocles

    what size engine did those chevy's have in them? Don't be to surprised about the bad mileage. A diesel service company i used to work for had several chev Z71's for errand and part delivery. The trucks used to be driven by the owner, and then he would buy a new one and make the old one a company truck. whenever employees drive a company truck, it is usually with the foot mashed to the floor at all times, because it's not their truck and not their gas. one of the trucks that got 15 mpg with the owner, was getting about 9 or 10 the next year when driven by the various hands.

    I will take back my comment on how gasoline engines are close to their refinement. I am a senior Mechanical engineering student, and i know that all it takes is some guy in a lab somewhere to make some amazing discovery to push ahead technology. but through my schoolwork and research, we are at a point right now where we are seeing close to the highest effieciency out of gas that the current engine designs can pull. did you know about 60% of the energy in gas is dissipated through the engines lubrication and cooling. engines today burn cleaner than ever. carbuerated engines emitted unburned fuel in the exhaust. todays engines get as much fire out of every drop of fuel. but there is still room for improvement. i think it's going to take a long time if ever though.

    To Aircat,

    the mileage is impressive in the vans. I did not know those numbers. Those vans are pretty heavy. i drove one with a 351 in it, and it got terrible mileage and was slow as a turtle. Ford may have tuned this thing just right to carry around those big trucks. i've never been impressed with the V10 concept because generally you are making more pistons that are smaller in displacement, which translates into more horse's and less torque. 410 ft lbs ain't the best in the truck world, but if gets better mileage than chevy's 454 and dodge's v10 (shouldn't have no prob beating dodge's), then I would say it is a good truck motor. can't wait to hear ya'lls report when you get your trucks.
  • BrutusBrutus Posts: 1,113
    The Dodge V-10 generates 450 lb-ft of torque, which I think is second only to the 500 lb-ft generated by the Ford Powerstroke diesel. The Ford V-10 generates 25 less hp and 40 lb-ft torque less than the Dodge V-10, but should get better gas mileage because it's a more efficient engine. We won't know if that's true until we get some data on the Ford V-10s. In another post, someone said that we should not expect the same gas mileage in the Superduty trucks as Ford is getting with the V-10 in the vans.
  • RoclesRocles Posts: 985
    All have the small block 305(5.0)V-8 engines. I understand about workers not caring about the treatment of these trucks. What I can't figure out is the one truck being so different than the others. All three have less than 50k on them to boot! The Rear is the same. The job duties of the three is virtually the same also.
    I just don't get it.
  • cdeancdean Posts: 1,110
    that is strange. i have heard of really simple things making that happen, like an oxygen sensor that is malfunctioning or maybe it got damaged during maintenance (employees are very good in that department either.) They are quite a few little sensors all over those Chevy's, and sometimes all it takes is one to confuse Mr. Computer and make gas mileage plummit. You should be able to (no guarantees) take it to the dealer, have them plug in their diagnostic computer, and if anything is not functioning properly, it's SUPPOSED to show up right away on the read out. maybe worth a try
  • BrutusBrutus Posts: 1,113
    And you are rotating drivers? And the tire size is the same? I'm sure you know both of these so it's actually insulting that I mention it, but I was surprised at the difference the tire size makes. Same trucks, same axle ratios, same engines, same style. You're right, it's strange, same workload.....It's not like it's Ford to Dodge to Chevy. If nothing at all is different, it's strange.
  • KCRamKCRam Mt. Arlington NJPosts: 3,516
    Since Brutus made mention, here are the current torque monsters in order:

    Ford/Navistar 7.3L diesel 500 lb-ft
    Dodge/Cummins 5.9L diesel 460 lb-ft (5 spd)
    Dodge 8.0L V10 450 lb-ft (fed)
    Dodge 8.0L V10 440 lb-ft (emission)
    Chevy 6.5L diesel 440 lb-ft (98 rating)
    Dodge/Cummins 5.9L diesel 420 lb-ft (auto)
    Ford 6.8L V10 410 lb-ft
    Chevy 7.4L V8 410 lb-ft

    Just remember - eight years ago, there was only one engine that made 400 - the Dodge/Cummins. Now we have a complete selection of engines that run cleaner and get better mileage while providing tree-stump-pulling grunt right from the factory.

    This is simply a trend throughout the aotomotive industry. Remember the original Escort in 1981? A planned 1.3L fourbanger was ditched just before intro, because it was way underpowered. Now Escorts, Neons, Sentras, etc. are all mini sports cars that still get mpgs well in the 30s, just like the old ones.
  • RoclesRocles Posts: 985
    cdean--yeah we even tried the computer to no avail. It baffled our mechanic also.
    Brutus---Actually, tires were a consideration for about a minute until I quickly took a gander at the great deal on Goodyear's we popped on the three and a Ford. It is a good suggestion, not an insult at all.
    I guess our truck is from the Twilight Zone!
    The only thing left to check is the spark plugs. We probably have the same but I refuse to let this go. Thanks all for the ideas.
  • lwflwf Posts: 223
    Rocles,
    I just scanned through all of the above looking for info about axle ratios on the the three. Brutus mentioned it, but I didn't see any specifics. You have approximately 25 percent worse fuel economy with one, but a lot of that could be accounted for if it had a much higher number for an axle ratio than the other two. Funny thing about axle ratios though, is that it's not obvious what it is. If you want to check out an engine's size and HP, all you have to do is pop the hood. I don't really know how you can check out what the vehicle's axle ratio actually is. It seems to me that there's not much of a cost difference during manufacture, and it might very well be the case that the vehicle came off the assembly line with a higher axle ratio than the buyer thought he was getting.
  • fredwoodfredwood Posts: 79
    Change the thermostat, its sticking. You may not notice a few degrees on your gauges but the computer will.
  • mharde2mharde2 Posts: 278
    You can find the code for the rear end in the vin#. The owners manual should tell you what the code translates to.
  • RoclesRocles Posts: 985
    Good suggestion but we confirmed that all three have 3.08 rear-axle ratios. We changed the thermostat yesterday and put new plugs in so I'll be waiting for the results. Thanks
  • lwflwf Posts: 223
    mharde2. I appreciate that info, and I wish it were the case, but I don't think it is. There certainly is no explanation of the VIN in my owners manual, but from what I can remember the VIN contains encrypted information that identifies only the vehicle model, the model year, the assembly-plant code, and the vehicle's serial number. However, nowadays, they put the VIN in a couple of places including on a label inside the driver's door jamb, and on that label is a lot of other data including one that gives "axle" and a number. In my case, it's "18". How that translates to 3.08, which is what I should have, is beyond me. But the point I was trying to make is even if you did have the translations, how do you know that's what's really in your truck? With the engine, you can count the cylinders to at least know whether you got a 6 or an 8, and there's usually other ways of identifying whether you got the engine you paid for. But with an axle ratio, the only thing I can think of is to jack up the rear wheels and count the number of needed drive-shaft turns to make the back wheels turn once. Hey, in one of the other topics, someone said his father ordered a Chevy truck and when it came in, it had some GMC trim on it (or maybe it was the other way around). If the factory can make that kind of a goof, putting in an axle that's different from what's marked on a lablel seems entirely possible........especially when the fuel economy is 25 percent worse than it should be and there seems to be no other reasonable explanation for this situation.
  • cdeancdean Posts: 1,110
    rocles

    tell me what rpm the engine turns at 60 or 70 mph and what size tire is on that truck, and i might be able to tell you your rearend.
  • lwflwf Posts: 223
    Sorry everyone, but I answered my own question regarding the axle ratio. I crawled under my pickup with a flashlight a few minutes ago, and there's a tag on the differential with a long number that starts with 3.08. That's what my sales receipt said I have for an axle ratio, so I guess the unit is marked after all.
  • RoclesRocles Posts: 985
    funny you mentioned it lwf---we did today also!
    We confirmed that all three have a 3.08 rear.
  • cdeancdean Posts: 1,110
    ooh, i don't like the 3.08s. except maybe for small regular cab trucks, this gear is just to tall, and doesn't give any better mileage in a truck that used for hauling, or a truck that does any town driving. I bet a 3.73 would get just as good mileage and run better. especially since you have a 305 which is not as torquey as the 350. fords and dodges may differ, but when buying a chevy, my feeling is get the 350 instead of the 305. In an extended cab truck or longbed, the 305 is going to be working just a little too hard, and you won't see any significant mileage increase by going with a 305. 1, maybe 2 mpg. the 350 will get good mileage and be a much more enjoyable drive. the only problem with the new chevys is the $800 difference between the 350 and the 305.

    does anyone know the mileage differences between the Ram's 318 and 360. the 360 runs great, but i know it likes to drink gas to the tune of 12 and 16. (town and highway).

    what about the new modular fords? (4.6 vs 5.4)

    just curious.
  • cdeancdean Posts: 1,110
    I don't think your diesel will be getting 5 mpg better than the v10. The only guy i know with a '99 powerstroke says it gets worse mileage than his old 454 which he got 12-13 with. the trucks were both crew cab 4X4s. But, he drives like a bat out of hell, and his math may not be very good. i'm waiting to hear other new powerstroke reports before i put all my eggs in that basket.

    still, the powerstroke in the past has never any major fuel consumption advantage to justify the $4500. except i guess if you only looked at ford and you're comparing it to the 460, which was a thirsty beast.
  • RoclesRocles Posts: 985
    cdean,
    Yes,you're exactly correct on the rears for our three 305 Chevys. We kicked that around but I couldn't let a great deal for these trucks slip by. We needed to buy two and these three were on the lot after a landscaper buisness ordered them but for some reason, that sale didn't go through. The dealer was stuck with them and I had to jump at it. It was a little over two years ago and I got them for roughly 15k each.
    I was wondering if it was feasable to change the rears in these trucks. Does anyone have any insight to this?
    Thanks for information cdean.
  • mharde2mharde2 Posts: 278
    Jim2, I am getting 17 in town, 21 hwy, 14 towing 6500 lb 5th wheel, with Cummins 24V. It only has 4000 mi on it so it should improve. I usualy drive 70-75 solo, and 60-65 towing.
  • cdeancdean Posts: 1,110
    rocles
    it's probably going to cost at least $200 to change out rearends. that just an estimate off the top of my head. you may want to check in to it, i don't know if your benefits will be worth the time and the money. the trucks will run better, but i don't know the type driving these trucks go through, and i'm not sure you will gain enough mileage to justify it. i have heard of people with a 305 and 3.42 rear getting 20 mpg highway. the 3.42 is still not a good rear in my opinion if there is going to be even moderate pulling or heavy loads. i think it is the best rearend for empty driving.
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