Spark plug vs. mpg?

[GNRick]

Has anybody experienced better/worse mpg after changing plugs? In theory, would a hotter plug (R44TS) give better or worse mileage than a cooler plug (R43TS)?

 

[83ttypecooled]

Hi,
I don't think there is a difference, unless you would get to the point of misfire with a really cold plug. I'm running R42TS, still the same.

 

[bruce]

Has anybody experienced better/worse mpg after changing plugs? In theory, would a hotter plug (R44TS) give better or worse mileage than a cooler plug (R43TS)?

Fresh plugs will work better then older ones, because of the lower firing voltage needed, and less likely hood of poor quality of spark. As a plug is used the sharp edges get rounded, raising the min firing voltage slightly.

TRs were never designed to be econo cars. That being said, with a razor sharp tune, that exactly matches the car, some good numbers are possible, but it takes alot of work.

Not to mention don't overlook the obvious, tire inflation, alignment, etc...