My findings, plain 87 is okay and gets the most mpg. 93 octane, maybe to hot hence the quicker burn off giving it the lowest mpg but overall good performance. #1 in my opinion is Derfs recommended 87 with techron. Median in mpg but performed better than the93 and at a cooler temperature. Thanks again Derf! Now back to coppercore plugs. Any recommendations? I like NGK,Denso, ac Delco. Think I'll stay NGK. Any input? Thanks to all.

 

I use the Techron to clean out the injectors every so often. You'll find that after a bottle through the system, your car will still run pretty smooth and the accel will wind up more smoothly. You don't need it in every tankful.

Appreciate the thanks in my direction, but thank the dudes who designed the engine and programmed the PCM--they did the work.

As far as plugs go -- stick with stock copper NGK BKR5ESA-11 plugs, now also known as NGK 5643's. Tried and true, probably 100 million miles on them and still the favorite of Saturn owners who see no need to reinvent a wheel that's not broken.

This NGK plug part number was only ever used for the Saturn S series cars. Even though it may be a clone of another plug, the engineers had their reasons for selecting it.
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$6 for a pack of 4 at RockAuto.com but gotta factor in shipping costs if it is the only thing you are buying.

$10 pack of 4 Ship to home fr Advance Auto -- dunno shipping costs here

$16 for a pack of 4 on Amazon but with free shipping

YOU make the call

 

Thanks for the input��