Hey, what gives? Just completed my suspension, brake and exhaust upgrade: Eibach springs, KYB shocks/struts, 15s (up from 13), 205 tires (up from 185), knuckles, calipers, rotors, pads, muffler, cat, and 2.25 pipe. All high performance.
Just ran through my first tank of gas, mileage dropped from 35 to 26 mpg for the same route! I thought the hi-flow cat and muffler would up my mileage. I know that there's a price to pay for wider tires and I have been driving a bit more aggressively, but 10mpg!
I do know that my engine is running a lot cooler now, but that should be a good thing. Any ideas about the sudden change?
Whoops, title should read "MPG drop".
With taller tires your wheels are turning more RPMs than your tach/odometer is reading. Your speedomter is probably reading slow as well. You will lose some mileage as you know but don't panic its not as bad as you think. (In other words you've actually traveled more miles than your odometer reads) I've never messed w/ the speedo on Js before, I think its electronic. On my Jeep its mechanical so all I had to do was swap in a different gear.
<img src="http://www.geocities.com/fudd_22602/elmer-shoot.gif"> Old school Js rock
Fudd wrote:With taller tires your wheels are turning more RPMs than your tach/odometer is reading. Your speedomter is probably reading slow as well. You will lose some mileage as you know but don't panic its not as bad as you think. (In other words you've actually traveled more miles than your odometer reads) I've never messed w/ the speedo on Js before, I think its electronic. On my Jeep its mechanical so all I had to do was swap in a different gear.
actually close but no cigar, its the other way around.. it has alot to do with driving habits, alot with maintenence. fuel ect..
**changes are here**
Went from 185/80 R13 to 205/55 R15 = same outer diameter.
Is it possible that my old O2 sensor can't handle the improved flow out the pipe and is making my engine run too rich?
Correction: 185/80R13 to 205/60R15, not that it matters because I don't think it has anything to do with that or the suspension.
I must have screwed-up the rear brakes somehow, while bleeding the system. The one-man bleeder valve I bought from Kragen's didn't work - wouldn't let fluid out at all! And l was pumping on the brakes with the drums off - really bright, I know.
So I played hell getting the drums back on. I was able to squeeze the left back down, but not the right. I put clamps across the pads and wiggled them back and forth while tightening them with everything I had, then (and I kid you not) I beat the drum on with a 2# hammer. That was Saturday.
If that isn't stupid enough for you, on Monday I re-adjusted the E-brake (a lot) because the brakes suddenly became soft soon after driving. On Tuesday the right rear internals must have re-aligned themselves because the E-brake was tight as hell. Long story short - I had the brake on!
Don't worry, I'm thoroughly inspecting the system tomorrow to make sure that whatever I f@#$-up, gets corrected. (I don't know how my poor Cavy has survived me for so long!)
