Gas prices are horrible. Engine options???

[mvfd70]

Gas is up to $3.15 a gallon here and my truck is no where near ready to drive. No telling what gas will be when I get my truck done. My current plans are to keep the original I6 and put a 5 speed tranny in it. Can anyone think of a better option for fuel mileage? I want a good comfortable driver out of my truck. It's not gonna be a worker.

I thought about diesel or ethanol and making my own fuel. That might still be an option, someday.

Anyone put a 4.3L in one of these trucks? How well does that work? Any other ideas appreciated.

[joedoozer]

I think that sounds like a pretty good plan. I6 is a great motor, not very powerful but it will run forever. And the 5 speed ( with OD assuming) should get you over 17mpg highway. Thats actually not that bad. Might even be closer to 19 mpg.

[mvfd70]

17-19 mpg would be good but I'm hoping for 20 or better. Might be a leap to think 20 but that can be a long term goal. Forgot to mention I've got 3.73 rear gears.

[dan42]

Remember that these trucks are like bricks going through the wind, with lots of resistance from the body, and from the older technology (rear end drag, brake drag, etc) that modern cars have less of. I don't even know if there's a full size chevy truck built now that gets over 20 MPG in 2008. Mine gets 12, and it's an '07.

[chrislehr]

Prius swap!

[MrBeast]

Originally Posted by chrislehr

Prius swap!

Did you know when you are driving down the road in a prius, and you stick your arm out the window, the car turns!

[skokie]

3.34 here in San Jose. Best I can get out of the 68 is about 14-16

[72swb_327stroker_?]

Originally Posted by skokie

3.34 here in San Jose. Best I can get out of the 68 is about 14-16

wow your only 45 miles away from me and 40 cents a gallon less!!!! thats almost 1 penny a mile, lol!!!!!!! its $3.799 a gallon for regular at the shell station by my house and i am still complaining! 9 bucks a gallon? i might be riding 1 of my bikes to work at that rate!...... i need to move, sf will be going that way soon with gas prices. my truck is lucky to get 6-7 mpg city, and maybe 10-11 freeway downhill with a nice tailwind and in neutral yeah these trucks suck! gas that is... mvfd70 how about a 6 speed trans and lower gears, maybe 308 gears? that could theoretically put you into the 23-28mpg range! it might be expensive but damn if it wouldn't be bulletproof! mileage-wise at least. a fuel injected 4.8l with a 6 speed, hmmmm, i think i might be selling my drivetrain to try that out! sweet!

[blukangoo]

I have to laugh when you all complain about the gas prices over there.

Right now we are paying 1.41 Euros for a Liter. = $2.07 a Liter
There are 3.78 Liters in a Gallon.
That makes the Gallon cost $7.82.

I wish I could drive over there when I need gas.

[72swb_327stroker_?]

Originally Posted by blukangoo

I have to laugh when you all complain about the gas prices over there.

Right now we are paying 1.41 Euros for a Liter. = $2.07 a Liter
There are 3.78 Liters in a Gallon.
That makes the Gallon cost $7.82.

I wish I could drive over there when I need gas.

well, if you really want to.....
you could ship it to me....
and i can fill er up!
you might not get it back right away, but i swear it will have a full tank

[DANTIP]

Two thoughts.

First I was in Delanco, NJ this week and saw gas at 2.71/gal.

Second, I replaced a tired 350 in a 72 SWB with a new ZZ3 GM crate motor and my mileage increased from around 10 mpg to 17-18. My driving habits are very fuel friendly but I was very surprised at the difference the newer motor makes. The aluminum fuel-injected V-8's are even better. Good Luck!

[blukangoo]

Originally Posted by 72swb_327stroker_?

well, if you really want to.....
you could ship it to me....
and i can fill er up!
you might not get it back right away, but i swear it will have a full tank

I might have to take you up on that.......when I win the Lottery.

[tdave00]

Originally Posted by mvfd70

Gas is up to $3.15 a gallon here and my truck is no where near ready to drive. No telling what gas will be when I get my truck done. My current plans are to keep the original I6 and put a 5 speed tranny in it. Can anyone think of a better option for fuel mileage? I want a good comfortable driver out of my truck. It's not gonna be a worker.

I thought about diesel or ethanol and making my own fuel. That might still be an option, someday.

Anyone put a 4.3L in one of these trucks? How well does that work? Any other ideas appreciated.

I've been pondering the same questions myself as I am preparing to build a truck. I have a running 250 i6 that a friend gave me and I have thought about going to EFI and electronic ignition controlled by megasquirt. I would probably back the 250 with a 200r4 and try to make the truck as light as possible. I have even thought of going with some 7/7.5 inch wheels for less resistance. I would definitely go with the 250 if I could find someone who had figured out TPI for the 250, but it seems to be a little bit difficult because of the siamese ports. Although you could still do throttle body injection with an aftermarket intake manifold. I am no expert but it makes sense to me that since these old i6's have so much low end torque that if you had the right rearend to run lower RPM's you might see some pretty decent gas mileage.

I like the idea of fuel injecting an old 250 but it might be more practical to go with a 4.8l or 5.0l v8.

[joedoozer]

I would change the rearend gears to something closer to 3.08's. With gears like that and a tranny with OD. That should be real close to 20 mpg. I will never complain about gas prices. It's cheap over here. I spent the last 10 years living and working in Germany and I have been paying over $9 a gallon for like 7 years. So I will pay $3-$4 a gallon with a smile on my face.

[Ol'Rover]

my 5.0L 305 V8(TBI) gets me around 20 - 25 mpg Highway and 18 or so in the city.

[dazza]

Interesting how gas prices seem to get higher as you get further into a major city. 72swb ... I'm close to downtown, in SOMA, and the Shell station near me is about the same, however, my truck lets me know how much she hates to eat that 89 octane crap! I just make sure I fill both tanks when I'm in the East Bay... $3.40 a gallon vs. $3.99 here!

So glad I finally got that aux tank fixed up.

[dazza]

Here's a question I've been thinking about lately, please, somebody correct me if I'm wrong.

After reading around here in the forums, I figured out what the size my truck tires probably were from the factory. I used some on-line wheel/tire calculators and verified what my speedometer tells me as well. With my bigger tires (33's) being 34.7 in diameter and the originals being 27.8 in diameter, the speedo shows about 11% slower than I'm actually going.

So I'm pretty sure that since the speedo and odometer are not electronic, the odometer is reading 11% slower as well, which would mean I'm getting better gas mileage than previously thought. Does that sound right?

If my calculations are right, I'm getting 12.5 mpg, which is about 2 more than I thought!

[ChevLoRay]

Gas here in central Arkansas went up (like everywhere else) at least .15cents in the past week. Still, I feel lucky compared to the other posters that I got gas Friday afternoon for $2.999/gal., at the WalMart on I-30. Eastbound. Benton. Exit 117, if you're traveling.

[Boog]

Filling up both tanks with lower priced gas sounds like a good idea at the time but you have to realize the additional weight being carried around costs mpg. Gas weighs something like 8 to 10 pounds per gallon I think. It adds up.
Someone should start a new thread with ideas on how to increase mpg. With that said I will.

[67shortie]

I put gas in the truck this morning at the tune of $3.15, 20 bucks worth just to commute to work, which is a 66 mile round trip. I do have some leftover at the end of the day though.

I was tracking this last night as well, I run a stock 1978 305V8 (175hp at best=SLOW), a quadrajet, headers, th350 and 3.42 rear gears.

I average 15.5mpg, driving freeway 80%.

I was figuring when the 350 gets done, with a mild HP cam (XE262) and stock vortec heads, quadrajet, and an OD auto I should be getting better with a light foot. I could be wrong though, the variable of the light foot worries me

[boostat4500]

I would recomend a 5.3 or 4.8 LSx and 4l60e swap. My burb gets about 13mpg on the freeway. And that's with a 6.0L, cam swap, 38x15.50" tires, crappy gearing (probably costing me 2mpg alone), and probably twice the weight you have. So I would think 20mpg or more would be easy for you, and you'd still have 300hp on tap.

[72swb_327stroker_?]

Originally Posted by dazza

Here's a question I've been thinking about lately, please, somebody correct me if I'm wrong.

After reading around here in the forums, I figured out what the size my truck tires probably were from the factory. I used some on-line wheel/tire calculators and verified what my speedometer tells me as well. With my bigger tires (33's) being 34.7 in diameter and the originals being 27.8 in diameter, the speedo shows about 11% slower than I'm actually going.

So I'm pretty sure that since the speedo and odometer are not electronic, the odometer is reading 11% slower as well, which would mean I'm getting better gas mileage than previously thought. Does that sound right?

If my calculations are right, I'm getting 12.5 mpg, which is about 2 more than I thought!

yeah, what sucks about that is thatis that my truck only runs high octane....like 109+! there is a gas station in south sf that i have to go to that actually sells pump-race fuel, now THAT is expensive!

[MrBeast]

I just did a NV4500 swap in mine, need to get it registered, it will be interesting to see what the 30% overdrive does for it.

[cruiserman]

It makes me smile to see folks contemplating spending money on a new engine to save a bit of gas. You're going to have to do a LOT of driving to make that worth while.

[mvfd70]

Originally Posted by cruiserman

It makes me smile to see folks contemplating spending money on a new engine to save a bit of gas. You're going to have to do a LOT of driving to make that worth while.

I tend to agree there, but I either have to buy an engine or rebuild the 250 anyway. Plus I don't have a tranny at all. So I gotta spend money either way.