Guys-

I did some searching and didn't find any threads regarding fuel mileage in all's respective trucks. Yes I know it varies when you tow. I'm just interested in mileage, specifically in trucks with auto trannies.

Post away!!!

Also the diesels come with 22 or 30 gallon tanks stock?

 

Mine is a 35 gallon tank but I got a 2nd Gen running gear with a 90 cummins in it so idle about the first Gen trucks But I get 18.48 at 75 to 80 MPH and I have the 47rh auto trans

 

i have a 91.5 thats gets 22 and my 93 gets 21 constantly when i brought the 93 home from nh i only got 15 running 70 mph i did some pump work my self and and now its up to 21 and same goes for my 91 i also noticed a slight improvement almost another mpg using lucas fuel treatment

 

21.5mpg last 3 tanks on my 89 with a 3 speed auto and 3.07 rear end. 1/8". bump in timing, little on the fuel screw, and rotated fuel cone. Line pressure in tranny slightly increased. Other than that: stock with a utility bed half full of tools.

Just fixed my speedo on the dually, so stay tuned on my mileage with an auto, Mud Terrains, dually, and 3.54 rear end. Used to do 18mpg or so by GPS before the timing was advanced.

 

My old 90 get about 18 hwy with 35" tires 4" lift and the usual suspect mods.

 

All of our trucks have 30 gallon tanks, 2nd gen trucks have 35 gallon tanks. I get 15.5 around town, without being too careful about the right foot. My best was 18.9 cruising highway @ 65 - 70mph. I think I could do better than that now though after a few minor tweaks. Depending on what I'm towing, around 12.5 - 13.5. Built A518 w. 3.54 gears.

 

19 in town and 20 even on the highway running 68-70 mph. 5 speed w/3.54's pump cranked up, maniac drivers (dad and i both)

 

Wish I had a 'rag^^^

 

My overall average in mixed driving - 60% city 40% highway - is about 19.5. Pure highway will run between 21 and 22 mpg at a steady 65 mph. Thats not bad for a truck that tips the scale at 7000 lbs and can generate close to 400 RWHP.

Bob

 

I'm normally just over 21, but my last tank was 23.3. 100 mile drive per day with 99% of that on the highway.

 

I get 21, 22 with a 100 mile round trip everyday, minor pump tweaks, fuel additive and royal purple oils

 

I drive 22 miles round trip 1/2 at 65, 1/2 on country roads, I think i avg.in the 16-17 range but its hard to tell (I CANT STAY OFF THE SKINNY), I drove it to the SDE in Terre Haute Indina last year and got 18.5, thats the best i have ever got. I normally don't drive out a tank without halling somthing.

Dar

 

The 2wd 89 SRW 5spd with 3:54 gears and 32" dia tires that I frequently borrow gets right at 20mpg in pure highway driving unloaded. It has no known mods other than pump bumped. I've been working on a 2wd 90 DRW with 5spd, 3:54 gears, and 32" tires and it is only averaging 16.5 in pure highway driving. Again only known mod is pump bump. In both instances I keep Mph between 65-70. Can't tell you RPM's since neither truck has a tachometer. I'd like to get the 90 DRW's mileage up. Seeing the mileage squarenose is getting with his truck gives me hope since my 90 is configured with a flatbed very similar to his. Researching DTW now for ideas.

 

Around 20 mpg, 60% highway. The best was 21.8 mpg driving 80mph. Stock 235/85/R16's tires, pump turned all the way up, pin ground thin, no AFC spring. Now, I have sense added a electric fuel pump and will be turning the AFC pin to the shallowest point and add the spring back.

 

Just bought the truck a two weeks ago and first tank through that was a mix of 3/4 two year old diesel and 1/4 fresh diesel got 21.3. Prob. 60% hwy and 40% city with a few hard starts to see what she had. On my second tank now same mix hwy and city but with 150 miles towing 5000lb trailer and running shorty exhaust for last 100 miles. 430 miles on the trip meter with a little less then 1/4 tank left cant wait to see what I get. Stock engine, star wheel turned 1.5 turns, fresh fluids and filters, fresh brakes and wheel bearings all around, shorty exhaust, and new today 235/85r16 dura grapplers.