Better gas mileage suggestions.

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SFROMAN

SFROMAN

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I am very intrested in hearing recomendations to increase the gas mileage on my 40. from the few times that I have driven it around I calculated my mpg to around 8 or 9. with thos numbers I have to constantly be stopping to refuel.
I am thinking converting to fuel injection and automatic tranny might bump up the numbers. what do you guys think?
Is 15 to 20 mpg possible?

Any suggestions, tips, advise, comments would be much appreciated.
 
SFROMAN said:
I am very intrested in hearing recomendations to increase the gas mileage on my 40. from the few times that I have driven it around I calculated my mpg to around 8 or 9. with thos numbers I have to constantly be stopping to refuel.
I am thinking converting to fuel injection and automatic tranny might bump up the numbers. what do you guys think?
Is 15 to 20 mpg possible?

Any suggestions, tips, advise, comments would be much appreciated.
Click to expand...

Fuel injection will increase your numbers, an auto tranny will take away from it again.
I don't really know what combo you are running but I think Jason told me a 350 sbc with a nv4500???..... just throw a holley pro flow injection kit on the chevy and it will drastically increase your numbers.
 
on top of what AL mentioned what kind of ingition system do you have a weak spark can effect mileage.
 
Del post up your setup and i'm pretty sure i'll have some suggestions for what you have.
 
Pull it with your diesel truck :)...or better yet buy a prius. I think you are talking about very small gains if anything. The additional cost of the equipment and time to get it right would be above anything you could save fuel wise. I bet you get close to 15 or more with your truck pulling it. I might just stick with that if it becomes and issue filling up all of the time.
 
Chevy 350, sm420, 4.10 gears, 35 mts. How about running 33x11s for daily driving?
 
And I thought SB Chevy's were supposed to get better mileage than the old Fs. Makes me rethink a conversion on mine.
 
its the sm420 that is killing his mileage.....

a smiple nv4500 swap would be great. Hollley injection would be better.


I know guys making upper 20's with over 600hp in their old camaros.
 
Are you correcting your calculations for the 35's. If not, you are likely actually getting close to 12mpg, not 8-9. I don't want to assume either way, but if you aren't sure on how to correct, take a gps and drive 10 miles per the gps and record the distance on your odometer. If odometer reads 9 miles, you are off 10%, 8 miles = 20%, etc. - Then just use that multiplier when you calculate your mileage. My guess is you are off a good 30% or so. I've never checked it in my 40, so I couldn't tell you either way. Also remember these things are shaped like a box - not good on aerodynamics. I think 15-17mpg is on the high side of realistic even with a 5 speed. I think Barry gets in the 30's, but his motor clanks a lot for some reason :)

:beer: R
 
Quick calc using in the stock tire for a 40, H78, vs a 35" tire proves to be ~25% difference. If you are showing 9mpg per the odometer, you are actually getting about 11.5 - worse than I have ever gotten in my 2F. When my weber was new and tuned just right, I could get 16-17 highway and 14-15 all day long.

:beer: R
 
I am going off of the rotal miles ran with amount of gas pumped into tank. I will get more accurate numbers this week since I will be driving it all week.
 
Del,

Im right there with you on this one.

I got the TBI and the mileage still sucks. I agree w/ above blaming the 420.
4500 swap party ??? :D
superhamom TBA

but then when you hit the trails youll want gears again, and thus the saga continues
(unless you just go ORION)
 
Hey, 6.34:1 ain't a bad first gear. Doubt you'd miss a 420 much there - and near identical to the 465.

:beer: R
 
but then when you hit the trails youll want gears again, and thus the saga continues
(unless you just go ORION)
Click to expand...


Not quite sure I understand this one. NV4500's can come with a 6.34:1 first gear:grinpimp:

You guys really need to look at the pro flow injection set.
 
I spend 75 to 80 dollars to fill up the f250 every Friday and normaly don't drive it on weekends. I filled up the 40 on Sunday with $24 and still have half a tank left. I will fill up again Wednesday evening. That tank should last me the rest of the week. So I get to drive my 40 and save at least $20 on gas every week. So I am in a win win situation.
Having said that, I want a new tranny. I'm ready for a nv4500 swap. The sm420 is Not bad but like mentioned earlier I won't miss it. I suppose I have to do so research and get smart on what it would take to do the swap.
 
SFROMAN said:
I spend 75 to 80 dollars to fill up the f250 every Friday and normaly don't drive it on weekends. I filled up the 40 on Sunday with $24 and still have half a tank left. I will fill up again Wednesday evening. That tank should last me the rest of the week. So I get to drive my 40 and save at least $20 on gas every week. So I am in a win win situation.
Having said that, I want a new tranny. I'm ready for a nv4500 swap. The sm420 is Not bad but like mentioned earlier I won't miss it. I suppose I have to do so research and get smart on what it would take to do the swap.
Click to expand...

Not a whole lot really.
 
Oh yeah, plus you'll have to rework the rear driveshaft, which will wind up being REALLY short with this application.

:beer: R
 
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