I'll be banned for asking this but...
 

I've got big plans for my car, and I'm leaning heavily toward a 454 LSX with a medium-ish cam (drivable, but mean). One of the concerns I have, though, is the mileage. It's not my daily and never will be, but if it's going to cost me $1 per mile in fuel, then I'd rather have it be slow.

So, what do you think the car will get mileage-wise? 3-4mpg? 7-8? 10? 12?

I know this will depend on how I drive, so to give you an idea, I typically get 14.5 on my current setup (see sig for details).. I'd probably switch back to 3.73s for the 454.

In the 10-12 area city I would guess. With all that modding you plan to do it might be wise to get a little beater car to daily drive anyway, something like a decent 4 banger. You dont want to rack up miles on a 454 lsx anyway if you dont need to.

Depends if you're one of those crazy carbed LS guys :eyes:

Indeed. I drive my wife's VW Golf most of the time and plan on replacing my POS Explorer (currently MY daily) with something more fuel efficient.




Nope. EFI all the way.



Thanks for the responses, guys. Does everyone agree with the 10-12mpg city? That's very tolerable, and I hope the 3.73s could make that a reality.

I Asked the same question do a search for 454 gas mileage or something like that or check under my name for started threads. Lots of hot answers!

Depends on how u drive it and what trans you wanna run through it..

a 6 speed, even with 4.10s and the 454 with cam, you can do over 10mpg, why not... I mean this is driving it decent and getting on it once in a while. you can even pull off better #s if you barely get on it..

Also some weight reduction helps..

i havn't gone to sleep yet but i'm still gonna go with at least 12mpg havn't even delt with big cubes personally. had a friend with a truck with an old school 454 and it was like 7 or 8 mpg in a truck but we drove that truck like assholes so as long as u bang ur m6 i think 12mpg is possible in town.

Its all relative. How you drive, size of the cam, efficiency of the heads what gears you have power to weight ratio. Its not like an old shcool carbed 454 that would eat a ton of gas just idling but cubes take more to feed so its not like your going to get great gas mileage.

My 427 Ls7 heavily cammed motor gets 26 mpg on the highway, this is babying the crap outta it, so you have to keep that in mind when calculating mpg. Its all in how you drive it, and how to tune it.

Best of Luck,
Adrian

454 LSX in my '98 T/A WS6. 6 speed with 3.73's out back. Pretty big cam.

I get @13.5 mpg in town, but on the open highway I average 21 mpg at 80 MPH, windows up and A/C running.

There was an article in Car Craft not too long ago about a 454 in a Trans am made 600rwhp and the owner said it got 18mpg with the ac on.

Nick

When I had my 383, I was getting about 8 mpg in the city. Of course it was in WOT more often then it was not :D

Keith

408 A4 gets 15/22. Just go a little smaller than you though. The cubes eat up gas more than anything, plus it will save you a lot of $$ to build.

-Geoff

That was my car. I changed a couple of tuning points, leaned it out some and went back to a 100 mm MAF instead of speed density tuning. The result was nearly exactly HP/TQ numbers and an improvement from 18mpg to 21mpg. Idle is much better as well with no surging.

i cant say what it gets in town as there are more WOT hits than there should be but on interstate my 402 still get 26-7