454 Lsx Mpg?
 

Hey,

Anyone know what sort of gas mileage ill get out of a 454 LSX with ITBs... 650RWHP. t400 with a 3500 stall.. not sure on cam, something with a mild to rough idle with lots of down low power would be going in. DAILY DRIVER.

THANKS GUYS


scott.

who would drive a 454 lsx and worry about gas mileage? thats a decent size stall... I'd guess about 7-8mpg High end...

Little>>>None.

Somewhere in the middle of there.

If you keep you're foot out of it and drive it like an old lady. But as someone asked - WHY???

Big engine + no overdrive + decent stall = don't plan on it being remotely economical to drive on the highway. If this is going to be a daily driver plan on just signing over a very large portion of your paycheck to the gas station.

Depending on your gear I'd say 6 to 9. Close to 4.10 gears, 6 mpg. 3.08 gears, maybe 9 mpg. Takes a lot of gas to turn that big engine that many rpms going down the road.

I get about 23-24 mpg on the highway, staying at an easy 70mph, and easy on the gas. I'm running a 500+ rwhp 427ci LS2, LS7 top-end with a pretty radical cam. I'm also running with a 6-speed, which makes it easy to keep rpms LOW when cruising. You're automatic setup is what is REALLY going to suck down the sweet juice. Now city mpg is a whole different story. Even I'm pushing about 9-10 mpg, which is not too shabby for the setup lol.

I have a VIG 3700 stall in my 427ci (500 RWHP) and in the CITY I get around 200 miles from a full tank. So if I use the 14 gallons and then I'm "EMPTY" and have to get more, so thats about 14 mpg. NOT BAD AT ALL for 500 RWHP. Highway cruising at 70 and I get about 25 mpg.

When I drive aggressively in the CITY on a tank I have to fill up at around 150 miles from that 14 gallons. So it drops to about 10 mpg.

Its more about driving casual and normal to get the best mileage.

But with your heavier tranny I would say you'll get 10-12 in the CITY if you drive casual. But once you get on it hard in CITY driving, with a 454ci, you'll be getting 7-8 mpg. Cruising on the highway, well you'll have to find your engines sweet spot. But I think you can get 20+ mpg.

There is no way he will touch 20 on the highway with a 3 sp auto. That thing will be turning 3K+at 60 with 3.73's

I'm with Bane, no way in hell, he'll be lucky to get 10 on the highway.

True. I had overdrive on my brain still. With a gearvendors OD he would though.

if ya got 15k to drop into an engine, you arnt worried about gas

What is the compression ratio?

Not necesarily true. A simple cam change can greatly effect economy. Cams cost the same no matter if it is a Dinosaur cam or a pussycat. If he is really planning on DD this car, then it could be a huge factor in his cam selection if nothing else. Remember an engine works on a scale of diminishing return, the mroe power you make, the harder it is to make the next one.:D

The engine in this case is not his problem with possibly collecting a decent highway mpg number, it is his driveline. That big stalled, non-od auto is KILLING him.

I don't know about that. I don't keep track of my mileage, but I wouldn't want to drive my car daily. I have 6 gears, but they don't get used between work and home. On base I rarely get out of 2nd, never over 3rd. I fill up about every 5th or 6th time the car leaves the house, although it leaves as a toy and gets driven like one. On top of the cost, I'd get tired of stopping for gas all the time. Until my daily commute is out a long empty stretch of road I'll just take the beater.

If your worried about gas millage, go with fuel injection. You should be able to get decent millage with that. High teens I would think, a c6 z06 get's 18/26. You should be able to pull somewhere around that with fuel injection.

Who care you have a 454! ! !

He is planning fuel injection. ITB

Do you already have a 454 or planing to build one? I wouldn't even consider it for a daily driver.

I just don't know why he's using a TH400, he should go 4L80E or even a nicely built 4L60E. Its just a street car, its not like its going to be launching hard on slicks at a track. He'll break the tires loose before he hurts the tranny or rear-end. I've got 500 RWHP/500RWTQ and I've had a 4L60E for 6 years and its only been rebuilt twice. Other than the tranny choice, it would make great daily driver MONSTER.

I run the LSX454 but I changed the A4 to a M6. At 70MPH in 6th gear I see just over 17MPG. With the T400 and stall you will be lucky to get 10-12MPG at 70MPH. Around town in stop and go traffic it drops quite a bit.

And I have to say, I love the 454 as a weekend warrior, but would not run it as a daily driver....no way.