My 240Z had about 240 HP and 38 MPG on the highway. Wasnt my MPG suppose to decrease if i added HP?

 

damn, I get 24mpg and thought that was good... how are you getting 38!?

 

I think you need to check your calculations.... 38mpg is HIGHLY unlikely... lil 4cylinder 120hp hondas barely make 35-38mpg.

 

Thats the point i dont know how and i'm using a RB26 engine on top of that. I gotta find out what i did to get it that high. (Or maybe its a computer glitch) But still just to confirm if you increase horsepower you might decrease MPG right? (Just confirming)

 

That's the basic idea.... for more power, you need more fuel... which means lower mpg. How did you calculate it? Just take how many miles you can go on a tank of gas, and divide it by the # of gallons the tank holds.

 

I added a computer turbo management system on my 240Z it calculates everything. Also would the decreasing MPG be alot on tuned v6 cars? Like how some 70's muscle cars have 7 MPG or worse the Bugatti Veyron that has like 2 MPG?

 

Is that management computer calibrated for your car specifically? Is it hooked to the speedo / throttle position / O2 sensor / fuel tank? If it doesn't know how fast you are going, what the throttle position is, or air fuel ratio, it won't have accurate inputs.

 

Why dont you just go fill your tank up completly... reset tripometer... drive for a good 200 miles doing highway/and city... then fill up remembering how many gallons it took... and divide miles by gallons.. for example here was my last one...

215 Miles and it took 13.27 Gallons to fill up

I had 16.20 MPG that was mainly City driving but about 60 miles of it was Highway...

If you cant figure out your MPG... how the hell do you have an RB26 in your car? do you make alot of money and had a shop do everything?

 

LoL... that thought went through my head too.

 

Thats krazy i drove my 280zx turbo from clovis new mexico to Albq New Mexico and back on a Full tank some 450 miles round trip... running premuim gas with octan booster ...

 

I need to buy a camera .

 

I spend all my money on mods (and some other things) .

 

Borrow somebody's digi cam!

 

Can i borrow yours ?

 

If you live in SLC I'll do a complete photoshoot of ya car for ya....

 

cell phone?

 

so you like photos eh? wink, wink, nudge, nudge, say no more! dude, never trust those calculators that are onboard the car, the rarely work correctly, go by the good old math. and id do mine, but its all friggin metric, i get 350km to 60 liters of fuel. thats aboot 20 mpg or something.

 

I get 35mpg occasionally but that's pretty tough to do, the whole economical driving at about 75 without accelerating or slowing down. Driving to california, in california and back i got an average of 28 miles to the gallon and in the city i tend to get 22 mpg, but I am far from 240 hp on my stock N/A 280ZX engine.

I agree with everyone else, fill up your tank all the way, reset your miles, when you go to fill up again, fill up all the way again, and divide your miles by the gallons you bought

wooo for Miles / Gallon nessssss

 

Of course .

 

Yeah But With Gas Prices These Days Who Can Afford To Do Even That???

 

I have a old digi camera you can buy. 30 bucks and thats shipped to your door my man... it's a decent kodak... giving you a deal to see this swap... so if you can afford an rb swap im sure you wont miss the 10 gallons of gas the 30 would buy... so how bout it? I'll even through in a copy of photoshop 7.0

 

I get 20-21mpg in my '82 280zx. That is city and freeway driving. But mostly city driving. Not too bad I guess, for how old the motor is. I think if I leaned out my AFM a little. It might get a little better. But yeah I agree with the people on here. Good old math is the only way to accurately calculate your mpg on a tank.

 

I checked the turbo boost system and its wired incorrectly i have to rewire it so it can work properly. .

 

Wires for the "boost system" ???? You talking about the electronic boost controller?

 

same thing popped into my head, minus the "boost controler thing" i am yet still confused.