Gas mileage

[lhracing]

I have a 2001 Chev 2500HD with the 8.1 and only get about 12.5mpg when unloaded and 6.5-7mpg pulling an enclosed trailer that weighs about 8500lbs. Your 13 on a carb does not seem too bad.

 

[skippy]

My tow rig is a 2004 Dodge 3500 4-door longbed with the NV5600 and 4.10 gears if i do 65mph and hold it there i can keep right at 21-22mpg and 17-19 towing, anything faster than 65 and it drops pretty rapidly. So im usually the guy getting flipped off in the slow lane cause im only 65 ....lol

 

[iamsparticus]

dont worry skippy im that guy too haha not only do i get people honking and flipping me off for going the speed limit but the wife always gives me crap but hey im in a old truck that drinks gas like brittany spears alone with a 24 pack

 

[Houndoc]

03 Montero Sport gets 16-17 (mostly highway). I lost about 1 mpg with the safari-style roof rack, plus a little when I first added the lift and larger tires.

Our tow rig, an 05 Ram 2500 Cummins gets about 20 mpg normal driving, 18 or so when towing the boat (6,000 lbs). I haven't had long enough trips with the heavier load of the horse trailer (closer to 10k with 4 horses) to see what that will be, but have a longer trip with it next month.

With trucks, you can improve by either removing tail gate, using a grate-style or adding a shell.

 

[iamsparticus]

i dont do shell's but a grated gate is in the near future

 

[jackjoh]

My 460 got 12 to 14 solo and 8 to 11 towing with 4.10 gears. The best improvement in mileage was obtained by changing the exhaust and K&N air filter. I had a friend in Cal. that said dual exhaust with a crossover increased his up to 17 with the same 4x4 gearing but I would believe maybe 15 knowing him.

 

[OREGON85]

My '85 Toyota (22RE, 33's, 4.88 gears, header and 2.25'' exhaust) gets 20-25 on the highway, if I drive 60. One time I was in a hurry and drove an average of 75, 70 one way and 80 the other, and only got 17.

 

[Silly Willy]

For you I would increase aerodynamics by keeping the tailgate down.

I don't know if you watch myth busters... but they busted this. You get better milleage with the gate up (something to do with an air bubble being formed in the bed).

You get best milleage (other than adding one of those fiberglass bed shells that are flat on the bed rails) by using one of those net tail gate things

 

[Tacoma]

'89 blazer, 4.56's, 35's, OD-- 11-12mpg avg.
'93 S10 blazer, no idea, little tires, OD-- 20mpg
'87 Chevy 4x4 dually, 4.10's, 33's, no OD, 85psi tires-- 9.5mpg no matter what
'67 M725 ambulance, 4.56's, 36" swampers, locked w/flanges, 8' tall, 460 engine-- 6.5mpg
various 1t work vans and trucks, variety of smallblocks on stock tires, some OD--12-15mpg

 

[Devel]

2010 Peterbilt 330 Rollback, 12 MPG unloaded 11 Loaded its consistently slow so i feel like an old man going up hills haha

 

[Cascadia]

2006 Toyota Tundra with 33s - 14 city, 17 freeway, 11.5 towing a rig to Moab.

 

[Unimog]

1997 Freightliner Century with single rear axle, rollback bed, and little 11 liter cummins. Non overdrive 10 speed and 2.65 gears. 13 mpg empty and 11.5 with 10k load at 65 mph. Looking to trade down to a pickup sometime in the next year.

As many others have mentioned, you are at a point with a carb and big block where only tiny improvements can be made.

 

[Rot Box]

91 F350 4 door 7.3IDI with ATS turbo, 5 speed, 4.10 R&P with 255/85 (33") tires. Here's the averages: I have noticed the fuel quality, temperature, and elevation among other things factor in for better or worse, but this is what I see here in cache valley.

16-19mpg highway unloaded
14-16 around town (14 is typically in the dead of winter)
10-16mpg pulling.

So 19 is the best I've seen and 10 is the worst in the two years I've owned it. I'm hoping for an improvement when I finally get around to a 4" exhaust and unrestricted intake...

As for the 460 and my $.02... I would deal with what you have and leave well enough alone. If you want something more efficient its time to part ways because you can throw all the money and time at it you want and you "might" get 2 more mpg. There are too many variables with that motor and vehicle/drivetrain especially being carbureted and no overdrive--not saying its bad--its a purpose built truck and poor fuel mileage is just the nature of the beast :-\

 

[LT.]

As for the 460 and my $.02... I would deal with what you have and leave well enough alone. If you want something more efficient its time to part ways because you can throw all the money and time at it you want and you "might" get 2 more mpg. There are too many variables with that motor and vehicle/drivetrain especially being carbureted and no overdrive--not saying its bad--its a purpose built truck and poor fuel mileage is just the nature of the beast :-\

This is very well put.

LT.

 

[Crankylove]

My daily driver/hunting/camping/exploring vehicle is a '86 F250, Extracab, longbed, 4x4, carbed 460, swapped in '89 ZF 5 speed, BW 1345, 3.55 gears, and 315/75/16 BFG mud terrrains. Around town, I get 10-11. On the highway at 65 mph I get 14-18 depending on where I am traveling. At 70, it drops to 12, at 75 it runs about 9 mpg. I have always figured that was pretty good for a 460 cubic inch V8 in a 6,200 lb truck with the aerodynamics of a brick.

Off road, cruising around (up to about 20 mph) with the hubs locked and transfer case in four high (with occasional 4 low usage) I get 12-14mpg.

Best thing I have found to help with mileage in my truck is to drive it like an old man, and put up with the ribbing from family and friends for being the slowest vehicle in the group.

 

[Maverick]

Originally Posted by Rot Box
As for the 460 and my $.02... I would deal with what you have and leave well enough alone. If you want something more efficient its time to part ways because you can throw all the money and time at it you want and you "might" get 2 more mpg. There are too many variables with that motor and vehicle/drivetrain especially being carbureted and no overdrive--not saying its bad--its a purpose built truck and poor fuel mileage is just the nature of the beast :-\

This is very well put.

LT.

x2

13mpg? That's about as good as you're gonna get. You can buy a lot of fuel for the cost of the upgrades to get marginally better mileage.

'02 td 7.3 eXcursion gets 9 to 25 depending on conditions. 11 around town and towing, 14.7 on the highway at 83mph. (25mpg at 55mph)
'81 tbi 454 jeep gets just over 10 doing 70mph on the freeway, no idea in town and on the trail.
'08 5.4 F150 supercrew gets around 13 (only calculated a few times)
'99 SFI 454 burb got 10ish
'81 carb 350 burb got 10-14
'87 EFI 4.0 cherokee got 17ish (as I recall)
'88 1.3 sammy got 20-25 and actually produced fuel while 4-wheeling.
'74 carb 396 blazer got 10
'73 carb 350 2wd 3/4 got 10-15
'85 carb 351 bronco got 10ish

YMMV

 

[iamsparticus]

So im not the only one buying gas like it is going out of style. I do drive teh truck like a grandpa. One of the biggest things that make it get worse gas mileage i think is because this engine is way smogged up it is way under powered for a 460! It makes you gas it alot up hills and such. Has anyone here had success in de smogging this motor and still passing the emmissions test, it passes fine now. For crying in the beer its got two smog pumps, a billion vaccum lines and a metal line from each exhaust port on the manifold that feeds it back to the engine

 

[benjy]

Get a Honda.... Seriously, do the math. Depending on the mileage, the difference in monthly gas expense will cover the cost of the payment. That's why the dirtymax only gets out of the garage a few times a month.

 

[iamsparticus]

I agree ben and thats why we have a Mazda 3 but the truck is for hauling a towing, unless your saying get another car and keep the truck in the garage

 

[Marsh99]

1985 4RUNNER: 3in lift, 35's km2 4.88 17 city 20 high way
1999 Tacoma: 31's km2 4.10 18 city 22 high way, towing 15 ( 2 wave runners)
My bro's 2010 Dodge Ram: stock with drop in K&N Hemi 15 city 22 Highway, Towing 13 ( boat)
My dad's 2010 Nissian Titian: Nismo intake, banks exhaust, 15 city 24 highway, Towing 14 (boat)
My dad had a miricle truck it was a 1999 dodge cummins W/banks kit 18 city 21 highway, 18 towing
He had 2 other newer cummins and the miliage was not close to that.

This is the sole reason I have to wheel a truck I can drive to where I am going. Having to have a tow rig, plus its gas cosumption, and buying a trailer would make my build funds non- exhistant. In my opinion new verus old is a catch 22. Either your rig was cheap to buy, and it gets bad mileage, or your truck payment is huge and you get a little better mileage. Plus the mantience cost on new and old.