• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

Boost pressure in relation to gas mileage...

Badfish740

New member
Joined
Aug 28, 2002
Location
Hamilton, NJ
Can anyone give me an idea of how bad gas mileage tends to get at higher levels of boost? First of all what kind of mileage should an '88 740 Turbo sedan w/manual trans get in stock form? Any idea what it will go down to at 1.0 bar? I'll be transferring to another school in the spring (70 mi from my house) and I'll home every weekend for work so mileage has become sort of a big concern for me :lol: I plan to do all the usual stuff to maximize my MPG like being anal about tire pressure and such. Of course my A/C doesn't work and I won't be using power steering. If I can get creative with the belts I might be able to run one off the crank to both the water pump and alternator-of course my engine is currently in pieces so I don't even know if this is possible yet. Is it?

Thanks,

Matthew
 
It all depends on how far you push you foot down on the "go" pedal. :twisted:

Fuel economy off boost will not change regardless of how much boost the engine is limited to or capable of. Cruising on the freeway, you will rarely be running into boost enrichment and when you do, you certainly shouldn't be hitting full boost. More boost requires more fuel. Keep your foot out of it and it won't make a bit of difference. Stomp on it regularly and it'll suck more fuel than a Suburban. :wink:
 
[quote:463049b17a]Can anyone give me an idea of how bad gas mileage tends to get at higher levels of boost?[/quote:463049b17a]

At higher levels of boot you always use more gas. If you want better mileage don't push your boot so hard, use a light foot.
 
The more power you make under enriched conditions the more gas you burn. After 3 or 4 PSi LH begins to enrich the mixture. The more time you spend past that point the more gas you burn. I haven't niticed any real difference, but most o the time I don't drive very fast.
 
I hav seen a MPG diference of up to 5 mpg depending on how I drive....Most of teh time I am going like a bat out of hell, but If I drive nice and slow and stay out of the redline then I get about 21 mpg (keep in mind that auto-trannies consume more fuel.)
 
Back
Top