Never seen a 12 valve with an overhead console mpg readout

 

Lets keep in mind the Canadian Imperial Gallon. I have learned one thing with the six speed. Running low on fuel and a long way to a truck stop, drop to direct and hold it at 2000 or 2100. There is a dramitic increase in mileage. How much? I'm not running 52 mph for a tank full to find out, it is dramatic though.

 

with my set up I get 18.5 RPM's below 2000. Don't think I'll get much better than that with my auto. but I'm happy with that.

 

Dieselminded - Let me ask you something ... Do you ever reset that overhead computer? I reset mine every fuel stop, before I pull away. I normally make a note of what fuel mileage the overhead says, and what I manually cipher. Just in case, to reset, push both buttons and hold them for about 5 seconds. The overhead display will blink on-off-on-off-on.

All of us guys with overhead displays should reset 'em and try again, and re-post.

- JyRO

 

I've kept a fuel record since 9,000 miles on my truck and I'm up to 45,000+ miles now. I haul a 8X8 trailer (with 2 cords of firewood plus the bed of the truck loaded with 1.5 cords) or my 1951 ***** Jeep to the hills to play (3,500#).

Empty - 7,900# - LWB - 3.55 Gears - 20.6 MPG Average

Hauling one of the loads - 17.9 MPG

I notice little changes in MPG. But when it starts going down I start looking simple thing like tire pressures, etc.

 

Well, my best has been 17.1 (empty). I only got 4800 miles on it. Going to and from work I get consistant 16.4 -.6. Going 70mph's for 200 miles I got 17.1. Will it get better? I'm betting that is what I will live with. Now, if I happen to drop it down to 60, I should hit 18 maybe 19, but that can't be realistic with highway posted @ 70. Now, with removing my 265's and moving to 285's, I'm sure a shaved off an easy 1 mpg. But my gasser couldn't match these numbers.

 

From Myrtle Creek Or. to Arlington Wa. 436 miles cruise set on 65mph 20.5 mpg.

Turn around trip, no cruise chasing Rip & diesel Freak down the interstate varrying speeds from 65mph to 85mph 16.8 mpg. Knocked almost an hour off the time going home & that was with a brief stop to drop off a inter cooler & grab a hamburger on the run.

 

My 96 gets consistent 15.5-16 mpg in town and on the highway. I figure it manualy every time I fill up. Now that is with adjustment for 33-12.50-16.5's. If I dont adjust the figure for tire size it is more like 13 mpg. I have 4.10's, long bed, ext. cab, 4x4 and stock auto. I dont complain much because the last truck I had was an 86 Chev 1/2 ton, long bed, 4x4 with an 87 L98 Vette motor. It got about 9 in town and 10 on the highway. It also had 33-12.50's on 15's. I guess a timing adjustment is going to be my only shot at better fuel economy without changing my set up.

 

If I understand your question it is related to fuel mileage with a vehical that is towing? If that is the case then eliminate the gassers. I don't think you will get the ilage on it and it will prolly not last as the wear and tear on a gasser is much greater. In fact IMHO I would choose the cumimins over any other moter out there this is where this truck relly shines. A 6 speed tranny will no doubt serve you well
Good luck

 

heres my $0.02 My dads truck stock 98 12v 4x4 2500 reg cab 3.55 gears and pizza cutter 33" tires and a big jeraco cap that sticks up over the cab and funnels air down between cab and cap (I imagine creats a bit of drag at speed) when empty gets about 22mpg average. he drives mostly highway and 97miles each way to work each day. Thats with about 230k miles on the truck. We've been getting the best econ by matching peak tourq rpm (what were saying is about 1700) to the speed you drive the most (for him about 70mph) to get the best econ. Were moveing up to 34.5" tires next to see if its it improves more still. So far its working well. The one time we pulled a load with that setup it was about 5000lbs (car trailer and car) we got 16mpg or so. I also hear advanceing the timeing some and a new camshaft is good for 1-2mpg each? I'm going to try that on my truck once I figure out how to do it
Chris

 

Infidel,

I think you are right about there being no overhead console in the first gen trucks. I asked my wife and she couldn't remember but I think I experienced a "false memory". Almost everything else I've owned in the past few years have the overhead console. My data is still unchanged tho. The 92 averaged 20 MPG regardless of the load (21 highway & 19+) mixed driving). If I can believe the overhead in my 04, it gets better milage (24-25 MPG highway-empty) but, it is 2 wheel drive.

Pop-Pop

 

I have almost 25k miles on mine, and typically get 19 mpg on the freeway doing around 70 and 17 mpg around town, but I also live on a hill and don't have much flat land around here. On our last vacation I got a bit over 20 mpg on I5 inland from the Bay area to central Oregon, which includes a fair number of hills and passes. I was doing 65 mph to 70 mph as it got dark about half way thru the stretch. On a long flat stretch of land I'm guessing that I'd get a few more mpg.

 

My 99 Quad cab auto 4X4 regularly got 22.4 mpg on the highway with the mich LTX/MS 265s going to a more aggressive 285 tire has dropped me to a best of 19 mpg but normally it runs in the mid 18s. Tires do make a difference as will keeping it at 2000 rpm. Put a set of Don's 1.5 EDMs in it. They will usually improve mileage.

 

best mileage truck, bone stock for steady 65mph:

reg cab (lighter)
4x2
auto trans (with locked converter)
3.54 gears
245 75R16 tires, smooth hwy tread (Michelin LTX AS) (small tire= less rolling resisitance)

Best mileage around town would be as above, only with manual tranny.

The farther way you get from the "ideal" truck, the worse your mileage will be. Since I have a QC 4x4, I think an easy 20mpg hwy is remarkable.

jlh

 

The best I can get is 17, and I drive conservativly (sp?). I would like to think that some 1.5 EMD's and an open 4" ex. would help, but it would take awhile for them to pay for themselves. Thats close to 1000k bucks, and that money is better spent on diesel right now. Especially seeing that im not independently wealthy. lol.