Mileage thread

[david85]

I really try to get as accurate results as possible with my truck. I drive the same 200 mile round trip almost every week when work is busy. This allows me to drive the first 100 miles on one tank, then the remaining 100 miles on the other tank going in the opposite direction on the exact same route and average the results.

Thats why I got as high as 24.9MPG, but don't claim that as my average highway performance. Going the other way dropped to 19 and change. Its hard not to stick your boot in it when you can burry the speedo at half throttle

I was able to get the low 20s on rare ocasions with the old C6 transmission too (and no turbo). But that required cool, and VERY humid conditions. Driving through light patchy fog in early autumn. Its not really conclusive, but it strengthens my feeling that mild water injection can help MPGs.

The numbers we see in the duramax seem high at a first glance, but when you consider thats with a 6 speed auto with 5th and 6th being overdrive, its not out of line. They are dealing with a final drive ratio very close to what I have with my single overdrive and 3.08s. The ford 5 speed auto still has the same overdrive as the older E4OD/4R100 tranny.

I've said it before and will say it again. Any stock body diesel (Cummins, chevy, duramax, powerstroke or our beloved IDIs) SHOULD GET 20 MPG if you can get the cruise RPM below 2000. Anything less, and something is not tuned right.

The fact that there are no EPA mileage estimates for these trucks make it a little harder to guess what they should be getting, so threads like this are the only real resource.

Welcome to the forum, Penzanse

 

[Clydesdale]

I really want to 6.9 an old ford cruiser car, or 6.2/early 6.5 say a 71 Riv.. and see what the mileage is.

I have the opportunity to buy a 77 LTD country squire waggy that the original owner claimed 18-20 on a road trip was normal.

I think a 6.9 which has proven to be more thrifty than a 7.5 in the same situation F250/350 could deliver a higher number than the 7.5... especially if I incorporated an AOD, of ZF into the equation, I am sure it has 3.07 (+-) gears.

 

[david85]

An old land boat with a diesel would be the best cruiser ever! Wonder if you can go any taller than 3.07s in the older cars. No towing worries either. ZF or E4OD would make it a great hipermiler. My truck can already reach 20 and a car would have about half the frontal cross section. I'd say 30 MPG would be possible.

I know this is a cummins in a chevy, but I'd love to see an IDI in an old LTD or Even a 66 Tbird:

http://www.youtube.com/watch?v=T9--ISeNexM&feature=related
http://www.youtube.com/watch?v=RO_kjaxIDzc&feature=related

 

[Michael Fowler]

I really want to 6.9 an old ford cruiser car, or 6.2/early 6.5 say a 71 Riv.. and see what the mileage is.

I have the opportunity to buy a 77 LTD country squire waggy that the original owner claimed 18-20 on a road trip was normal.

I think a 6.9 which has proven to be more thrifty than a 7.5 in the same situation F250/350 could deliver a higher number than the 7.5... especially if I incorporated an AOD, of ZF into the equation, I am sure it has 3.07 (+-) gears.

A turbo 6.9 in a 65-67 Ford Country Squire would be a sweet ride. Probably have to put beefier springs under the front, but it would be neat to do the conversion "all ford".

 

[TLBREWER]

I have a '66 Impala SS waiting for restoration in my back yard. It will be getting a diesel transplant...just haven't decided which engine yet. At about 2/3 the weight of my truck or less, I'm thinking 30 plus MPG should not be a problem. Add to that more HP and Torque than it came with (396) and it should be a pretty fun ride.

Now where did I hide that time and money to get this project done....

Tom

 

[Optikalillushun]

1988 F-350 RCLB Custom
7.3N/A
ZF 5 speed
4x4
3:55 gearing
intake mods, exhaust, G code injectors and a fresh pump, trans/tcase/rears run syn erl
315/75/16 tires ran at 50 psi

with my aggressive driving i see 14-16 in town (agressive is shifting 3,000-3,500 or more) with a mix of normal driving (shifting around 2200). on the highway i can see up to 18-20 cruising at 70-73 (usually around 2,000). when my dad was using it and driving normal he was seeing 22-23 (70 highway/30 town driving). i just took a trip about 180 miles highway and 120 are town driving so ill see what i can muster up. i corrected the speedo for the tires. i am very pleased such a big truck can get this good of milage.

my 93 F-150 XLT 4x4 with a hopped up 300/E4OD/3:55 and 33" tires only sees 12-14 no matter how i drove it.

 

[Fozz]

92 F350 crewcab dually, E4OD, 4:10 rear, ATS turbo and downpipe, 6700lbs empty I get 13 in town. Freeway-14, but I'm in California and have to drive 65 -70 (in the slow lane!). Last trip with my 10K 5'r was 8.5 (65mph) but that was a lot of long steep hills and head/cross winds.

 

[RLDSL]

92 F350 crewcab dually, E4OD, 4:10 rear, ATS turbo and downpipe, 6700lbs empty I get 13 in town. Freeway-14, but I'm in California and have to drive 65 -70 (in the slow lane!). Last trip with my 10K 5'r was 8.5 (65mph) but that was a lot of long steep hills and head/cross winds.

70 mph in CA.. I'm surprised you don't get pulled over for obstructing traffic No joke, I once got pulled over at 2 am in CA on the 210 freeway for doing the speed limit.... the cop told me the reason he pulled me over is because the only people doing the speed limit at 2 am on that road were drunk

 

[91f2504x4]

70 mph in CA.. I'm surprised you don't get pulled over for obstructing traffic No joke, I once got pulled over at 2 am in CA on the 210 freeway for doing the speed limit.... the cop told me the reason he pulled me over is because the only people doing the speed limit at 2 am on that road were drunk

I wonder if he was wrongly taught that was probable cause for a traffic stop, or if he just likes illegally pulling people over , I have seen guys that will pull people over like that and then when they actually find an offense they will try to make up some pc for the stop and more times than not all their charges are thrown out in court.

 

[Diesel JD]

Around here it seems like the traffic courts are rigged, that they always side with the cops unless you can PROVE the cop broke the law.

 

[91f2504x4]

Well that is just the opposite of here, it seems like you could have a signed confession and a video of the crime being committed and more times than not, the charges would be dropped.

 

[k_williams1982]

I just drove almost 500 miles today, and checked my mileage. I have a C6 automatic, 4.10 gears, 315/75R16 tires, and the truck weighs 7,200 pounds. I have a set of "BB" injectors, and the pump is turned up two flats. When I went over to punkmechanic and typ4's places, I checked the mileage and running at 2,700 rpms (65 mph) I got 17.4 mpg on the highway. I thought that there had to be an error somewhere in my results due to the C6 and low gears, so I checked the truck again today. I ran the truck today around 2,500 rpms (60 mph) and sometimes a little faster. Including hauling a 600+ pound bike back in the bed, I got 17.6 mpg today. Since I used a WMO blend, I made the trip from Bend, OR to Medford, OR and back on about $36 of diesel. All together, I put about 470 miles on the truck from 7:00am until 6:30pm tonight including purchasing and loading a motorcycle, stopping for lunch, and stopping for some pics on the way back.

 

[RLDSL]

I wonder if he was wrongly taught that was probable cause for a traffic stop, or if he just likes illegally pulling people over , I have seen guys that will pull people over like that and then when they actually find an offense they will try to make up some pc for the stop and more times than not all their charges are thrown out in court.

I see you've never driven southern california freeways. 55mph speed limit, nobody is doing under 85... especially at 2am when there is no traffic to hold them back. The cops basically don't bat an eye unless there's something out of the ordinary, aparantly, actually obeying the law is out of the ordinary
Gotta remember which state we're talking about here

 

[ameristar1]

I have a '66 Impala SS waiting for restoration in my back yard. It will be getting a diesel transplant...just haven't decided which engine yet. At about 2/3 the weight of my truck or less, I'm thinking 30 plus MPG should not be a problem. Add to that more HP and Torque than it came with (396) and it should be a pretty fun ride.

Now where did I hide that time and money to get this project done....

Tom

The guy that owns Nitrous Express has a Dmax powered Mustang that ran in the 9's during Hot Rod's Drag Week, while averaging 33-35mpg. Drove it everywhere, ran it 900 miles back to the home base. There are some videos of the car running on Youtube and Streetfire.

 

[Dirtleg]

With all this talk of mileage and old car + diesel I will spill the beans on the project I have been planning next.

I am going to take this car;

You must be registered for see images attach

and put a diesel in it. My buddy had a 6.0 + 5r110 out of a wrecked 250 that was the original idea but it is physically too tall (without turbo) to clear the hood and I am not willing to alter the hood.

So next is the "other" 6.9 I have in the shop. I think that with a custom intake and a dry sump i might get it to fit. My other thought was a 4bt dry sumped and mounted on a slant.

My reasoning for this would be as a commuter. I drive 80 miles a day and would love to get 30+ mpg's. Current rearend in the Plymouth is a 2.93 and I got a 4r100 at my disposal as well so it could be doable.

As it sits the Plymouth gets about 16 on hwy (383 and 3 speed auto).

End hijack.