Only Premium in my SS from day 1.

SPPD

 

93 octane all the time. Premium is 1 98 here.

 

Run premium but going on a lengthy cross country, 10 day road trip whenever I am out of hilly terrain and simply highway cruising I see no need for premium fuel. In my day-to-day (mixed) driving I run premium because I believe this sweet ride deserves it.

 

Why not do a test, couple of tanks of 87, couple of 92 on your trip.
My thoughts are the SS "can" safely run on 87, BUT anytime an engine that is created for best performance on 92 is run on 87, it is backing the timing back. Any mechanic or racer will tell you that if you back the timing back from optimum, you reduce efficiency, which translates to less power, less mileage. Can you measure it? Try it and find out. Let us know.

 

The same reason you only get a couple of weeks of good performance from an exhaust or intake mod on the SS is the same reason why the first one or two tanks of fuel won't give you a real performance evaluation. The ECM gradually learns and adjusts, while trying to keep engine output at a nominal level. The data obtained with the first 1-2 tanks of fuel will be invalid.

 

The thing that everyone keeps forgetting, is that it's not ALL about fuel economy with this. We are talking about engine knock and detonation which in turn means blown motors. Ya'll are driving a performance vehicle and being more concerned about fuel economy then longevity of the engines life.

 

 

It's a different reason. You're confusing fuel trims with knock retard. LTFT's may well take a couple of weeks to settle in, depending on driving habits. Knock retard is, by definition, almost instantaneous. It has to be because severe knock can destroy an engine in seconds. Octane scaler is an extension of knock retard. Depending on KR severity and duration, spark can be scaled back to 0% (low octane table) in less than a minute. Also, spark advance doesn't affect air / fuel ratio (the basis of fuel trims) unless it's off by an amount that would barely allow the car to run, if at all, so LTFT's are, for all practical purposes, unaffected by fuel octane.

 

LOL XXL!

LT1 and NEBUlous,
How many miles or months do I need to drive on 87 to get lower mileage?

 

In the carburated days when you had no control over knock except to physically take timing out I would agree with the run premie only.These days where the knock is control instantaniously and the maker say recommended and not required as they do in other vehicles of the same calibur,run what ever you want.Its recommended because alot of people who buy a performance car tend to drive them as such,while others here KNOW how to drive a performance car with the fuel they have.As said,if your into TOP performance and drag times and such,run nothing but.If its a daily driver,run regular.We all bought this vehicle for our own reasons and we drive them differently,so let your habits dictate type fuel.I tend to think most people who don't understand fuel qualities tend to over do the fuel thing.Like those running premie in a car "tuned" for reg.The SS will run on both,it all depends on what YOU want it to do.I'm with Cleveland,I have seen no difference in milage,only power.As this vehicle has a brain of its own that compensates for the lower fuel.If it only takes 150 HP to cruise at 60 mph where does 220hp come in except for quicker times to get to that speed?190 hp does fine for the way WE drive the car.The nice thing is..we have a choice of 3 diff blends..those that have cars that REQUIRE 91 or better do not.Once the stage 1 kit goes in I lose that choice,so be it.If gas gets overpriced again I may even return it to stock specs just so I have that choice again,while everyone else can empty their pockets.And ..oh yeah..The owners manual "recommends" lots of things..do you follow them all? Or do you use your own brand/style/procedure or whatever.