View Single Post
  #4  
Old 02-25-2019, 05:08 AM
e39_touring e39_touring is offline
Member
 
Join Date: Mar 2007
Location: Seattle, WA
Posts: 300
e39_touring is on a distinguished road
Quote:
Originally Posted by Bdc101 View Post
Do you have data to back that up? Nothing about intake and exhaust mods should ever change MPG in gasoline engines. Power yes, mpg no. That's not absolutely always the case, but it's so rare that I'm always skeptical unless there are fuel logs showing it to be the case. (Not dash readings)
The trip computer is VERY accurate. Afterall, your ecu knows EXACTLY how much fuel it is injecting into the engine at any given time and how many miles since reset. By the trip computer, I could never do better than just shy of 21 mpg on highway trips, and now I'm getting just shy of 24 mpg on the same routes.

Intake and exhaust mods can very well change the efficiency. Ever hear of pumping losses? Think maintaining 600 deg temperatures in a catalytic converter is done without expending any energy? You often hear that an inefficient exhaust system only costs 2 or 3 hp or such and such, but when the vehicle only requires 20 to 30 hp to maintain it's speed on level ground, there's your 10%.
__________________
2012 xDrive35d
2001 BMW X5 3.0i 5MT
and two 1987 Corvettes - Callaway Twin Turbo and Guldstrand Grand Sport 80
Block Tester
Reply With Quote

Sponsored Links