Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Bought the car with headers all the way back to a giant catback

brucepick · 08-09-2011, 09:32 PM

I understand how + why headers and fat pipes would help on a car that runs at or near WOT and between say, 4000-6000 rpm (assuming red line somewhere between 6-7K).

But if you're going for max mpg you likely run at half that rpm range or less, and nowhere near WOT. So where's the benefit of the huge capacity exhaust system? I've always read/heard that you do need SOME back pressure. Running at low throttle and low rpm's I'd think there's precious little back pressure even with a stock exhaust.

08-09-2011, 09:32 PM	#7 (permalink)
brucepick OCD Master EcoModder Join Date: Dec 2007 Location: Eastern CT, USA Posts: 1,936 Outasight - '00 Honda Insight Team Honda Gen-1 Insights 90 day: 54.18 mpg (US) Thanks: 431 Thanked 396 Times in 264 Posts	I understand how + why headers and fat pipes would help on a car that runs at or near WOT and between say, 4000-6000 rpm (assuming red line somewhere between 6-7K). But if you're going for max mpg you likely run at half that rpm range or less, and nowhere near WOT. So where's the benefit of the huge capacity exhaust system? I've always read/heard that you do need SOME back pressure. Running at low throttle and low rpm's I'd think there's precious little back pressure even with a stock exhaust. __________________ Coast long and prosper. Driving '00 Honda Insight, acquired Feb 2016.