Longtubes and gas mileage
Thread Starter
Instructor
Joined: Dec 2005
Posts: 100
Likes: 0
From: Austin, TX
Longtubes and gas mileage
How did longtubes impact your gas mileage? I just read a post where someone said that they lost 5-6 mpg going with longtubes. This doesn't make much sense to me since you're essentially reducing pumping losses with a freer-flowing exhaust. I picked up a solid 2-3 mpg after installing headers on my LT1 Camaro.
Also, I can't immediately afford a dyno tune after installing longtubes. If headers adversely affect gas mileage that much and I don't tune it right away, I'm wondering if they're even worth the trouble.
Also, I can't immediately afford a dyno tune after installing longtubes. If headers adversely affect gas mileage that much and I don't tune it right away, I'm wondering if they're even worth the trouble.
Team Owner
Joined: May 2005
Posts: 23,682
Likes: 9
From: Flagstaff Az.
Long tubes
I have an 04a4 that came with 3:15s. I picked it up in Fla. and drove it back to Flagstaff, Az., and put another 3000 miles on it getting 29-31 on the road at 80-85mph. In July of last year I had jet coated long tubes installed along with 3" RT hi-flo cats and SS Works 3" x pipe and 3" exhaust all the way out. The mileage remained the same. I probably lost some mileage due to the larger size exhaust, but probably picked up the difference in the hi-flo cats. I recently went with H/C package, 3:42s, and a 3500 yank. Mileage dropped to 26-27. You will probably have to have the after cat o2 sensors deleted if you put on long tubes or put in the Simms. Hope this helps. 
Last edited by tiojames; Feb 21, 2006 at 04:00 PM.
Burning Brakes
Joined: Jan 2004
Posts: 1,243
Likes: 6
From: Rowlett Texas
I saw no difference in my milage when I drove the same as before I installed the headers. The problem is, a different sound will come from having headers and you'll want to go on out another 500 or more rpm 'cause you like to hear it.
The best I ever got was 29+ mpg driving betwee 75 and 80 mph on a trip.
Just took a much shorter trip with the top 1/4 tank being all urban driving and got 28.7 mpg.
The best I ever got was 29+ mpg driving betwee 75 and 80 mph on a trip.
Just took a much shorter trip with the top 1/4 tank being all urban driving and got 28.7 mpg.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
My 02 Z06 was getting 28-30 MPG highway and 17-18 combo city highway. Adding Stainless Works Headers, high flow cat, 3" mid-section with X pipe and high flow mufflers dropped my mileage way down! I went from 30 highway to 23- 24. I had a tune and now I'm back up to 27-28. It isn't the best tune and I plan on tweaking it to optimize everything. I'm still running a bit rich.
Yes.,,, headers can destroy your mileage if you don't get your car tuned.
BC
Yes.,,, headers can destroy your mileage if you don't get your car tuned.
BC
