I average 10 MPGs. Mostly in and around town. Not a whole lot of highway mileage.
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.
Lets hear some MPGs
- Thread starter LIVEAnimals
- Start date
Mutt gets 10, 11 with the BB..
but I got 16 consistently out of the stock K5 350 TBI, 700r4..
but I got 16 consistently out of the stock K5 350 TBI, 700r4..
ripperoo187
1/2 ton status
I get 10 mpg highway with a tailwind drafting a scared Prius. 
4 inch lift, 1 tons 4.88, 39.5 Boggers
tbi 350 700r4
4 inch lift, 1 tons 4.88, 39.5 Boggers
tbi 350 700r4
The best I got was 15.3 on the way to Missouri this summer rolling through Indiana.... 35's, 3.73's, 700R4 and a 350
What gets me is I used to drive my 72 K5 with its original 350 (with over 100K on it) and with various 4 bbl carbs like Q-Jets and Carter AFB's ,back and forth to work 70 miles each way,and get a consistent 13-16 mpg with it...the commute was mostly high speed highway and some rural hilly roads,and I didn't putt along at 55 mph like I was supposed too then either (you'd get rear ended if you did!)..
I had a TH350 in it at first,them swapped in a SM465,with the original 3.08's in it I couldn't shift into 4th on hills and it lugged under 45 mph,so it probably increased the highway mpg some..
I think todays ethanol laced gas is the reason we cant get decent mpg,not so much the trucks or engines..alcohol has less BTU's than gasoline and thus runs leaner and you'll need to burn more to get the same power..also its oxogenated so it'll burn faster..probably flows thru the carb jets faster too...
I noticed an immediate drop in mpg back in the 90's when they started forcing us here to use oxogenated fuels and "gasohol"..when I drove to TN in my G10 van in 1992 I noticed it ran better and gas didn't seem to get guzzled as fast down there--not only was it cheaper than here,they still had "real" gasoline,not this half ethanol crap..soon as I filled up here it ran with less power and tended to lope at idle,and got worse mileage..
I had a TH350 in it at first,them swapped in a SM465,with the original 3.08's in it I couldn't shift into 4th on hills and it lugged under 45 mph,so it probably increased the highway mpg some..
I think todays ethanol laced gas is the reason we cant get decent mpg,not so much the trucks or engines..alcohol has less BTU's than gasoline and thus runs leaner and you'll need to burn more to get the same power..also its oxogenated so it'll burn faster..probably flows thru the carb jets faster too...
I noticed an immediate drop in mpg back in the 90's when they started forcing us here to use oxogenated fuels and "gasohol"..when I drove to TN in my G10 van in 1992 I noticed it ran better and gas didn't seem to get guzzled as fast down there--not only was it cheaper than here,they still had "real" gasoline,not this half ethanol crap..soon as I filled up here it ran with less power and tended to lope at idle,and got worse mileage..
THRILLBILLY
1/2 ton status
havent driven Thrillbilly in months, but last time I checked going by GPS I was getting between 4-6 MPG... 
89' K5 350 TBI 700R4 NP208 1 tons, 44's 4.56's.
89' K5 350 TBI 700R4 NP208 1 tons, 44's 4.56's.
CaneyCat
Registered Member
I'm getting 11.5 consistently out of my K5 with no lift and 31''s... Really hard for me not to lift it seeing as everyone gets the same mpg with lift and bigger tires. I drive 30 miles to work one way, so some of yall should not feel bad about driving 7-10 miles to work lol But I would not trade DD'ing my square or living in the country for anything!
I know this is apples and oranges...
my 2WD 90 R2500 regularly gets 17 on the hiway...
6.2/400 14bsf 3:73 stock 265/75R/16's
I keep thinking about a 383, but then I find these mpg threads...
Glad I'm not a speed demon anymore.
my 2WD 90 R2500 regularly gets 17 on the hiway...
6.2/400 14bsf 3:73 stock 265/75R/16's
I keep thinking about a 383, but then I find these mpg threads...
Glad I'm not a speed demon anymore.
My odometer doesn't work, but occasionally I check my mpg by filling up between my destinations and keeping up with distance via gps
With my 350/th350 3.73s and 33s I was getting 11-13
Now I have a tuned 4.8l/sm465 with 3.73s and 33s and if Im nice I can get 17-18 on the highway traveling about 60-65. In town and back and forth to work (lots of hills) I average 14-16.
With my 350/th350 3.73s and 33s I was getting 11-13
Now I have a tuned 4.8l/sm465 with 3.73s and 33s and if Im nice I can get 17-18 on the highway traveling about 60-65. In town and back and forth to work (lots of hills) I average 14-16.
The most important part about this thread is that now I don't feel bad that my odometer doesn't work 
I've thus never calculated but.... My sense is somewhere around 9-10. Less if I have my foot in it, which I often do, especially if I've been driving the Jeep. I have a beat up old 350 w a manual.
Incidentally, my 2.5 manual Jeep has NEVER done better than 19-21, not even when it was new, and not even at 55mph. It has 31s on it.
The concept of anything above 25 blows my mind.
Lucky I ride my bike a lot.
I've thus never calculated but.... My sense is somewhere around 9-10. Less if I have my foot in it, which I often do, especially if I've been driving the Jeep. I have a beat up old 350 w a manual.
Incidentally, my 2.5 manual Jeep has NEVER done better than 19-21, not even when it was new, and not even at 55mph. It has 31s on it.
The concept of anything above 25 blows my mind.
Lucky I ride my bike a lot.
Pretty consistently 16MPG, FWY only. There is some MPG I'm leaving on the table, eventually I'll add those to it. Rig specs are in my sig. Offroad I am right around 10MPG.
OP, 4.10's and no OD are hurting you if this is freeway driving (55MPH+), but I'm also guessing you haven't fixed your speedometer being off, so any calculations you have made will be incorrect in any case. Pointless contemplating MPG if the figures used to calculate it are flawed.
OP, 4.10's and no OD are hurting you if this is freeway driving (55MPH+), but I'm also guessing you haven't fixed your speedometer being off, so any calculations you have made will be incorrect in any case. Pointless contemplating MPG if the figures used to calculate it are flawed.
Last edited:
black dawg
1/2 ton status
10-12 2500 burb 465/205 3.73 and 235/85-16 tbi454
11-15 1500 burb 700/241 3.73 and 235/75-15 tbi350
11-15 1500 burb 700/241 3.73 and 235/75-15 tbi350
350/700r4/33s/4.10s/4 inch lift with 3/4 tons---11-12mpg, mostly city.
It used to be about half that until I realized the choke wire was intermittently connected and the mixture solenoid wire was corroded and it was running pig rich all the time.
An advantage of having the Comp 4x4 cam is it doesn't take much gas to get it moving, but the 80's smog heads run out of flow quick. I'm hoping a Vortec head swap will net me some better performance without taking too much of a hit in the MPG department.
It used to be about half that until I realized the choke wire was intermittently connected and the mixture solenoid wire was corroded and it was running pig rich all the time.
An advantage of having the Comp 4x4 cam is it doesn't take much gas to get it moving, but the 80's smog heads run out of flow quick. I'm hoping a Vortec head swap will net me some better performance without taking too much of a hit in the MPG department.
sixb
1/2 ton status
Mine gets 41-49 mpg and i still ride my bicycle almost everyday.
That is very true.
both the ethanol and the lack of lead makes for worse fuel economy.
Same thing with the diesel ulsd made us lose about 20% mileage.
I was getting 30-32 mpg with my blazer (465/205/3.08/35") with the Perkins diesel, and I want to get that engine back in a truck to see what kind of mileage I will get now.
ion
1/2 ton status
32.8
2012 Scion tC 2.5L 6 speed auto running 19 pounds of boost.
2012 Scion tC 2.5L 6 speed auto running 19 pounds of boost.
454Sub
5/8 ton status
Gearing a vehicle close to stockish to compensate for the increased tire size would really help some of you. 40s on 4.10s is murdering your gas mileage.
CGT80
1/2 ton status
My 79 C20 pickup was getting 10 mpg with mostly freeway driving and closer to 8 mpg with a lot of city traffic. Towing a 9,000 pound trailer gave me about 6 mpg. Engine was a 10:1 406 sbc with a comp 270h magnum cam. Heads and intake were worked over and the carb was small at 600 cfm. Th400 trans, Gearvendors overdrive for a 0.78:1 ratio overdrive, 4.10 14bff, 33" bfg at's on the rear. I drive it like I stole it. I should get the engine and trans back in next week after have them rebuilt. The engine is now 10.2:1 with a comp 264h roller cam and roller rockers. I am curious to see how the cam change works out for bottom end torque and fuel mileage. The old cam ran hard to 4800 rpm and still pulled good to 5500. After I get 500+ miles on the engine I plan to throw my 795 qjet back on the truck. The 600 edelbrock gave me better mileage on my 383 but that engine also wasn't built like this one. I need more air now.
My 88 K5 has a 350 tbi (new) 700r4 (recently rebuilt) np208 and 10 bolt with 4.88 gears and 315/75-r16 mud tires which sit under a 6" lift. This one gets 10 mpg as well but city driving doesn't seem to be as bad for it as the 406 (the 406 puts out twice the power, and I run it hard so it is very capable of using big quantities of gas).
Both of my speedometers are calibrated and show withing 2-3 mph while driving at 65 mph.
My 88 K5 has a 350 tbi (new) 700r4 (recently rebuilt) np208 and 10 bolt with 4.88 gears and 315/75-r16 mud tires which sit under a 6" lift. This one gets 10 mpg as well but city driving doesn't seem to be as bad for it as the 406 (the 406 puts out twice the power, and I run it hard so it is very capable of using big quantities of gas).
Both of my speedometers are calibrated and show withing 2-3 mph while driving at 65 mph.
