aldive said:Ideally you should also pick up some gas mileage. Let us know.
--------------cherrybomb said:For you, and anyone else interested.
I've run about two tanks of gas through it since this tune-up with the indexed plugs.
While I don't have a very good highway miles test like you usually do Al, my daily commute is a constant. I drive a little over 3 miles each direction from my house to work and back, about 2/3 of which is on the freeway. I haven't deviated from that in the last two tanks.
On average, I'm still getting ~12mpg I could imply a .1 or .2 increase in mileage, but I'd say that's well within the margin for error.
So, on the mileage front, I'd say it's a wash.
As far as performance, the truck is definitely more responsive, and throttle response is better. I don't really think I picked up more power per say, but it's smoother, and more responsive.
All in all, not sure I'll index my plugs again, but it was a fun exercise.
Perhaps sometime later, I'll do a more scientific test, where I intentionally "index" the plugs toward the piston instead, and do a repeatable driving loop, then do the same again with plugs "indexed" toward the intake valve instead.
In theory, it seems like it would make a difference. But the old addage seems true here.
"In theory there is no difference between theory and practice, but in practice, there is."
Edit: I remembered finding someone else who did a much more scientific test than me. If you're interested in reading it you can find it here
-----------cherrybomb said:Well, keep in mind I was also replacing quite possibly original wires and spark plugs. No doubt a large part of the improvment I felt had to do with that, rather than indexing the plugs.
Part of me wants to believe that my extra effort had some positive result though.