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-   -   Less Fuel? (http://www.focusfanatics.com/forum/showthread.php?t=252769)

blackbumpinfocus93 03-10-2011 04:05 PM

Less Fuel?
 
hi all! idk if anyone has noticed but the SCT X3 ECU Flasher motto is "More Power! Less Fuel". I understand the More Power! part but nobody ever talks about the Less Fuel part. To me thats a big selling point and I was just wondering if anyone has this particular flasher and could tell me if they actually are getting better fuel economy.
[ffrocks]

iminhell 03-11-2011 12:11 AM

Not speaking for them, just generalizing.

'Less fuel' can be somewhat of an ambiguous term. The general public doesn't understand the difference between better fuel economy and better MPG's. Fuel economy is the mass amount of fuel required to produce X hp. MPG's are how far you go on a gallon of fuel. The two aren't necessarily related.
*pulling #'s out of my ass
Take a Geo Metro and a Chevy P/U. The Metro got around 45 MPG and made 50hp. The Chevy truck gets about 17 MPG and makes 300hp. 50 divided by 45 = 1.1. 300 divided by 17 = 17.6. Meaning that per gallon used the Chevy is more fuel efficient than a Metro. Even though the Metro gets better MPG's, most all of which has to do with weight of the vehicles. The best example of a good balance I can think of is a newer Corvette. 400 some odd hp and you can get 30+ MPG highway with them pretty easily. Very efficient car in all regards.

Long winded but what all that means is the SCT may be thinking efficiency vs MPG. Though it is possible to improve both if you find the right tuner to help you.
For example if you wanted better highway MPG's you could tune leaner closed loop or back off the timing a bit. I can't recall the numbers off hand but there is a formula to find how many hp it takes to sustain a certain speed. IIRC 60mph is something like 30hp for the average newer car. So it doesn't take a ton of power but you need enough or the engine luggs and you end up using more fuel.

illinipo 03-12-2011 03:42 AM

Quote:

Originally Posted by iminhell (Post 3588979)
back off the timing a bit.

Nope! In general the same things that help power also help fuel economy. It is a game of efficiency. The glaring outlier to this statement is open loop afr, obviously.


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