05 wrx - better milage oil and plugs

[Sam Soltan]

Is synthetic oil worth the costs? If so any recommendations?

Would a "hotter spark plug" yield better mileage? if so what
recommendations.

 

[Edward Hayes]

Hotter spark plugs will not improve your gas mileage. I changed to
Mobil 1 in the engine and both differentials and did improve my
mileage by .4 mpg. The gas mileage improvement will never cover the
cost of the extra oil money for synthetics. You best method to improve
mileage is to feather foot the throttle on accelerating and anticipate
the traffic lights.

 

[Rick Courtright]

Hotter spark plugs will not improve your gas mileage. I changed to
Mobil 1 in the engine and both differentials and did improve my
mileage by .4 mpg. The gas mileage improvement will never cover the
cost of the extra oil money for synthetics. You best method to improve
mileage is to feather foot the throttle on accelerating and anticipate
the traffic lights.

Thanks, Ed! Similar results here...

As to "hotter" plugs for the OP: the heat range of a plug is designed to
burn hot enough to keep it clean (from fouling) without getting so hot
as to cause pinging or pre-ignition. With computerized fuel management,
there's seldom a need to change from the mfr's recommended heat range
unless you're REALLY off the chart with your driving style (long hours
at way above normal speeds, similar long hours sitting idling in cold
temperature traffic, those kinds of things) or you've got a SICK engine
you're trying to limp along a little further (for example, we used to
put "hotter" plugs in oil burners....) Stick w/ what the book calls for
and you should do fine.

Rick

Rick

 

[Sam Soltan]

Thanks for the reply ... that's what I thought, and wanted a confirmation.