View Full Version : Gas mileage after race kit install??

02-08-2008, 02:40 AM
Just wondering the gas mileage of your xb12 after intake,exhaust,ecm upgrades.


02-08-2008, 06:02 PM
A performance upgrade may enable you to accelerate and ride faster, which would necessarily use up more gas. On the other hand, if you continue to ride gently and cruise at only moderate speeds like you did before the upgrade, your mileage may improve a little (despite the richer ECM settings), since your engine is working a little less to suck in air and blow out exhaust. For example, if you're a commuter, you might find you can be lighter on the throttle, upshift a little sooner, and maybe run at lower revs on average during your day-to-day usage, which may result in better mpg.

Caveat is I don't really know -- it'll be a couple of years before I can test this theory. I considered upgrading, but decided to wait until the warranty expires (many reasons -- I can elaborate later if you want). In any case, gas mileage did not figure at all into my decision, but that's just me.

02-08-2008, 06:41 PM
No usually when you do mods like this your mpg gets worse. But the power more than makes up for the 5mpg loss you got.

02-08-2008, 07:59 PM
I would usually get 38-42 mpg on my XB9R with a Race Kit

The Kelzer
02-26-2009, 05:00 AM
Sounds crazy...but i get 50-55mpg with the race ecm and exhaust muffler on my 04 12S. It's warm year round here and the roads are fairly straight...oh and I'm older now so I've only had her to top speed 2x in 4 years. [smirk]:(

02-26-2009, 11:01 AM
if theres a big drop in gas milage theres a drop in power

teh Nub
02-26-2009, 11:43 AM
if theres a big drop in gas milage theres a drop in power

You have that backwards more fuel & air = more power.

02-26-2009, 01:32 PM
talking big drop in mileage...the correct air fuel more power i agree... just getting more air and fuel is not automatic power gain......loss of mileage is not and automatic gain eather...if theres black soot build up on your exhaust your running to rich and losing power somewhere in the power band..gain of horse power in the upper rpm because of more air need gas yes...v twins get 100% cylinder fill in lower rpm no matter what exhaust your running thats why toruqe drops to gain hp with free flowing exhaust.......its a fun subject....look at dyno sheets that a shop is pushing a product for exhaust...the before and after...they have sometimes as much as 30 runs to show a small gain.....but i agree more air you can make more power

teh Nub
02-26-2009, 01:59 PM
Since he was talking about ECM upgrades, I was expecting people would look at it as a bike running efficiently. Even with the mods and actually tuning the bike correctly, it would probably see better fuel mileage, but who is going to putt around to actually see any of it...