Yep, went ahead with the 93 as well. New ride, best to get it started on good stuff.

 

I ran 87 for the first 1600 miles as told to by the dealer, when I went back and complained about the spark knock, they said it was designed to run on 93 Since then all I have run is 93 and the mpg is up 3 mpg and the performance is definately better. At only .20 per gallon more and getting 28-30 mpg, I'll stay with 93 octane.

 

I tried both and could not tell any difference and my mpg was the same too, never had a pinging problem. But I used 93 octane when I pulled my Harley to Florida and back for bike week. Got 24.8 mpg pulling a 650lb bike on a 310lb trailer at 70+ mph.

 

I use the 93 octane,get better mileage also a smoother idle in town

 

The computer in the car will adjust the timing and the spark as well as other things according to what gas you put in it. I know on my Cobalt I allways run 89. I did 1 tank of 87 and saw a drop off of almost 1.5 mpg.

 

I get better gas mileage and noticeably smoother idle/better power with premium.

 

This forum is paying off already! I'm not a gearhead (no offense) like a lot of people here. Fishing, I know... cars, engines, etc... if it's not changing a headlamp or jump-starting a dead battery.. I'm useless. Just ask my wife. But seriously, try the veal.

Anyhow... I've only had my 06 LT2 for 2 weeks and I've been running 87 Octane and getting 24.7/27. After reading this thread I put in 91 for 20¢ more a gallon and now I'm getting 27/30 and at times 31 HWY! It runs better too. Next tank I'm gonna try 93.

Thanks to all for the tip... now who has a good way to mount a fishing rod holder?

 

I only run 91 myself but I've been thinking about trying a little 100. Could it hurt anything you think?

 

Not sure. Funny story though.. i gave a friend of mine (a Ducati Mechanic) an old snow blower of mine and he put racing fuel in it for grins. It threw snow for about 120 ft and screamed like a jet engine! 72.4 seconds later it shot out a blue flame about 3 ft and blew the engine. My ears are still ringing.

What was your question again. My scotch needs a refill.

 

87 works fine in the winter in Michigan, but in the summer when temps go > 80, using 91/93 gives a noticeable performance improvement. Octane requirements increase with air temp increases (unless you are running an inter-cooler).