73-87chevytrucks.com
General Site Info => General Discussion => Topic started by: 84chvy on December 06, 2011, 12:54:10 pm
-
hey guys i was just wondering what everyone got on mpgs. give me your setup and mpg. ex. motor/trans/rear end gears/tire size/tire type/engine mods.
-
Rebuilt 350 with a hearty cam. SM465 trans, 4.10s, 33x12x16(285/75r16) BFG All Terrains. Last time I checked im getting 8-10, but that was when I had 31's. Id guess 12-13 now since I had a tune up and the bigger tires.
-
thats not good.
-
GM performance 350 with 330 hp th400 trans stock gears 31x10.50-15 general grabbers at2 tires. the last time i checked i was getting around 12 mpg
-
86 4x4 scottsdale 3/4 ton 6.2diesel stock tires, and everything stock
18mpg
-
1985 C10 305 TH350 2.73 P205/75/15 15.6 mpg
1985 C20 454 4 speed 3.21 gears LT235/85/16 load range E 15 mpg
1985 C30 350 TH400 4.56 gears LT265/70/17 load range E 12 mpg
All taken mixed Highway/rural and all trucks have over 100K on stock engines with stock quadrajets
-
thank you for all the replies.
-
Sad part is I should be getting better then what I get. 1975 Chevy 350 tbi stock out of an 87 gmc 700r4 trans 3:73s pushin 33" savero m/t half town half freeway 13.1mpg that's the best I've ever got. My 84 2wd with a 290hp crate 350 with true duel exhaust flow tech headers running a 600cfm Edelbrock 700r4 and I believe 2.08 rear gears got around 7-8mpg but when I pulled that motor and put it in my 62 impala with a 3 speed on the column and unknown rear gears gets around 17mpg with factory exhaust manifolds and a offenhouser intake and Holley 570cfm carb. Not to mention the impala tachs around 1200 more rpms at freeway speeds then my 84 did.
-
1986 lwb 305 700r4 2.73 peg leg. i get 13 mpg even with a leaky carb and esc dist.
-
I get a little over 11 MPG in my '91 V3500 with the TBI454 and 4L80e with 4.10:1 rear gears on 35's with 8" of lift. Now that was a mouthful! :D
-
yeah, I'm digging up old threads.
Tell me if I'm crazy, but I bought my 91 V3500 300 miles away from me, and the whole way back, mostly interstate (~70-75mph) I scored 20 mpg. Small block 350, 4L80E, stock everything. Checked the math three times, still came out to 20. Sounds insane, right?
-
Bluecrew,i agree. 20 mpg's from your set up does sound insane.
Trust me, I don't question your math, just keep in mind when people change gears and tires the odometer does not read accurately.
-
I hate to say it, but there's no way you're getting 20.
-
speedo is off possibly. i can only make a rough estimate of maybe ten. 350, quadrajet, 425 propane carb, 3.23 gears possibly, 4wd with stock tires, a heavy ass flat bed, and 80 gallon fuel tank on the back
-
I get 14.5 or so mixed driving, 255/60/15 3.73 rear, sm465, fresh tune up and rebuilt qjet all on a 350. That factors in how heavy my foot feels on any given day too.
-
I get 12
-
Bluecrew,i agree. 20 mpg's from your set up does sound insane.
Trust me, I don't question your math, just keep in mind when people change gears and tires the odometer does not read accurately.
I hear ya. I did have a stock setup, fuel injection, and I babied it all the way home. I have since lifted it and will slap some 35's, but I will drive it around for a little bit on stockers to see how much the mileage is before the tires. 300 miles, 3/4 tank of fuel, and my monkey math. maybe I am crazy... I still haven't checked what gears I have... I did check the speedo with my gps, my phone app, and the wife driving my stock intrigue.
-
'80 2wd, swb, lowered 2", 275/60/15, nv3500 5 speed. no a/c
engine is a 350, mild cam, flat top pistons, vortech heads, edelbrock intake, holley 670 street avenger, flotech headers, magna flow exhaust, balanced and dyno tuned. I also installed an electric fan and removed anything emission related. I get 17-19 in the city and 19-22 hwy. I'm not sure what the ratio is but it is stock.
The engine has very good low end torque and I can just about idle everywhere. Down the interstate the rpms are fairly low in od. in forth they are fairly high (forth gear is a 1:1 ratio)
-
I used to average about 8 mpg when mine was my daily driver. My driving habits varied a lot though. Occasionally I would baby it but I would work it hard, drive it normal, have fun with it on the street, or wheel it. ;D It was usually a fun 8 mpg!
-
1982 C10 Suburban 6.2 700R4 3.08 LT30x9.50 28-31 mpg
1990 V2500 Suburban 4x4 Cummins 6BT NV5600, Gear Vendors, 3.73, 2" lift, 265/70/17, 26-27 mpg
1996 Chevy Tahoe, 4x4 Cummins 6BT, NV4500, 3.42, 6" lift, 35" tires, 22-24 mpg.
-
My 1Ton Crew Cab with the 350TBI/4L80E would get 17-17.5 running about 65 mpg, so if you are off, it isn't by much.
-
about 12mpg, 350 with quadrajet and th400, 31.5x10.5x15 all terrain
-
I get about 16mpg on the freeway at about 65mph.
78 3/4 ton 2wd / 350sb / th400 / 3.73 rear / 33.5" tires /
Truck weighs about 5400 lbs with me in it.
I'm real easy changing speeds, i don't accelerate quickly, Try not to use the brakes (I stay like 10 car lengths or more behind the car i'm following) (mainly to prevent rock chips on the front end though)
Dunno the in-town mileage, never checked it. I only check it on long trips (150 miles one-way or more)
Speed kills MPG in these things. I found if I go 60-65mph I get about 16mpg. IF I GO 75mph or higher though, i only get around 9mpg or less.
I've noticed too, on NON-OD trannies, I get better mileage with the WINDOWS UP and THE A/C GOING, than with the windows down and the A/C off.
This doesn't work out quite like this for OD trannies in my experience. REMEMBER: They didn't wind tunnel test these trucks with the windows down. that makes a lot of drag. And keep your tailgate up. it may or may not give you like .002mpg more, but the sand your tires kick up will ruin your paint if you drive around with the gate down all the time.
Also when running your A/C: if you don't have it set to full cold, it doesn't run the compressor as much. use MAX but don't set it to full cold. use max and set it to what's comfortable. the A/C doesnt have to work as hard using MAX because its cooling already-cool air from the cab and not just strictly hot outside air.
The best way to improve mileage really is to control your foot, like my dad told me, drive like there's an egg between your foot and the gas pedal. don't break the egg.
another trick is to put a vacuum gauge in your cab, and watch it while you drive. the object here is to make the needle move as LITTLE AS POSSIBLE while driving. it will always move, you just try to minimize the movement. It's HARD! haha!
-
my 1978 GMC C25 350 Qjet sm454?(3 speed with granny) hm posi rear end (3:73?) last I time I check I was getting 13mpg with a leaky tank no tune up and apparently a bad fuel pump lol when I get the pump on I will see what I get, my goal is 15mpg ^_^
-
Best I ever got in my 86 k10 was 16mpg all hwy averaged 9-12 in town depending on how hard I beat on it. 3.42 gears 31x10.5 350 040 over 9:4.1 cr 214/224 cam longtubes no cat single 3 in exhaust th350 2800 stall . I miss that truck :/
-
my 1978 GMC C25 350 Qjet sm454?(3 speed with granny) hm posi rear end (3:73?) last I time I check I was getting 13mpg with a leaky tank no tune up and apparently a bad fuel pump lol when I get the pump on I will see what I get, my goal is 15mpg ^_^
Sm465. It is a four speed, but you rarely use first (low gear).
-
I have no idea what my truck is running especially as the UK & US gallon differ I believe.
I was of the understanding these trucks rand gallons per mile!
-
I have no idea what my truck is running especially as the UK & US gallon differ I believe.
I was of the understanding these trucks rand gallons per mile!
well actually for most of us its Smiles per gallon, which is priceless. 8)
Costs me $60 per week to get complimented, and many offers of cash, and to be driving something I LOVE 100 times the way i love my focus. ;D
-
went to a small roadtrip last weekend and figured that i got 18mpg, driving mostly at 55mph. happy with that :)
350 with q-jet and th400...
-
Got a tad above 20 mpg towing this from WA to TX. The flip side of the coin is I paid as high as $4.40/gal for diesel and had to use 2 different credit cards to fill up the tank.
(http://img.photobucket.com/albums/v136/Ventura/P1030293.jpg)
-
I have no idea what my truck is running especially as the UK & US gallon differ I believe.
I was of the understanding these trucks rand gallons per mile!
well actually for most of us its Smiles per gallon, which is priceless. 8)
Costs me $60 per week to get complimented, and many offers of cash, and to be driving something I LOVE 100 times the way i love my focus. ;D
Very true- the smile and the admiring even from the people that don't want to look if ya know what I mean!
I dare say I was getting 4-5 mpg on the last two runs, mostly 'cos the passengers wanted me to hold back from the traffic then nail it so they could hear the sounds, needless to say I happily obliged.
Checked the plugs and it's running rich so a carb rebuild and tune is now due.
Still, like yourself, I'd drive the truck 1000 miles instead of 50 miles in my toyboata poo estate car.
-
454 Holly 650, TH400, 205, 4:10 with 36" tires.......6.5 mph. I got you all beat!!!!!!!!!!!!!!!!!
-
1985 k10 swb with canopy, 6.5 diesel, banks turbo system, marine injectors, 700r4, 411 gears (with elec. lockers f/r), old style goodyear MTR 33/1250r/15............ 22+ mpg hwy driving easy, 60mph
-
I filled my tank, drove 470 miles and when I refilled my tank it took 27 gallons out of 30. Equals out to 17.4 mpg. Its on my 89 GMC V2500 Suburban with a 350 4.10's and 35's.
-
Mine was getting 12 mpg as I stated earlier. I have since installed a Skip White distributor when mine crapped out. The ad said 65000 volts and it was $49.80 to my door. I installed it, regapped my plugs to 44/1000 from 40/1000 and my mileage is up to 14 on the highway plus it runs a lot smoother. Pretty good return for under $50.00 .
-
i have to say concerning mpg is that you are not going to get really good mileage out of these trucks unless you go either:
a) diesel
b) LS series engines
c) move down on cubes, i.e., 4.3 v-6
Due to the size, weight and aerodynamics of these trucks plus the gen 1 smallblock, you are not going to get stellar mileage. You can only refine and make improvements. This is not nessesarily a bad thing as you are still saving money vs. buying a newer truck or a newer/different drivetrain.
-
I foresee my next round of mods netting near 20mpg. TBI, Exhaust and 5 speed. With 13-14 I get now with my qjet, stock exhaust and SM465, a 5-6 mpg jump sounds reasonable.