Do I have to use top shelf gas?

[dan326]

In the gt, it is recommended/ required to run premium gas. Is it okay to run 91 octane?What is the difference between 91 and 93?What problems will I have (long and short term) if I am running 91

[Kari]

There are a lot of threads about this, but the bottom line is yes, you need to run premium, or else you risk damaging your engine. Search for "premium" and you should come up with several threads where this has already been discussed

[03VibeGT6Spd]

In someplaces 91 is the best you can get.I have ran 91 a few times but the performance really suffers.I run mostly 93 but, if I'm going to be running hard I run 94.

[dan326]

I have been running 91 from shell. They have 93 as the top shelf gas.From previous threads, I have learned that 91 or higher is okay in the gt.What I don't get is that if there is a 93 that I can use, is it better than the 91?If there is both 91 and 93 to choose from, is the 91 considered a mid-grade?I did run 93 from shell before, and I thought that my car was driving more roughly than when I use the 91 from shell.I have also heard about the ECM. I posted a topic about it to get more information, but some insight would be helpful and appreciated.

[03VibeGT6Spd]

I notice the difference, while I'm in lift.91 runs but 93 and 94 makes a very noticeable difference in power.when I run 93 I only use BP gas,94 I buy at shell.I have noticed that some gas stations sell gas that they call 93, but it runs like 91.So I do watch where, I buy it now.If your not going to be pushing your car 91 will get you by.but whats the since of having a high performance engine, if your not going to use.

[ragingfish]

As it says in the manual:Quote »If your vehicle has the 1.8L H.O. DOHC engine(VIN Code L), use only premium unleaded gasolinewith a posted octane of 91 or higher. In an emergency,you may be able to use a lower octane -- as lowas 87 -- if heavy knocking does not occur. Refill yourtank with premium fuel as soon as possible. Otherwise,you might damage your engine. If you are using91 octane or higher-octane fuel and you hear heavyknocking, your engine needs service.You shouldn't experience a noticeable variance in performance with 91 vs. 93. If you are, try a different brand of 91 (see top tier gas, next paragraph). The engine was built around 91, and putting 93 in would, in my cases, likely yield the same performance gains one would get by putting 91 in a car designed for 89 -- none.General Motors endorses the following gasoline brands as "top tier" gasoline: QuikTrip, Chevron, Conoco, Phillips, 76, Shell, Entec Stations, MFA Oil Company. These gasolines meet a recently established new standard for gasoline performance. "TOP TIER Detergent Gasoline help drivers avoid lower quality gasoline which can leave deposits on critical engine parts, which reduces engine performance. That’s something both drivers and automakers want to avoid. "