FAQ-53

Super or regular unleaded?

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First, let me make this distinction. Pre 1981 cars do not have the ability to change the timing if the engine is pinging. Cars and trucks made after 1981 have a on board computer that will see the engine pinging and retard the timing to eliminate the ping. Then the computer will try and sneak the timing up, all the time watching to see when the ping comes back. When it does, the timing is moved back a couple of degrees to eliminate the ping.

AAA says only 5 % of the cars on the road today absolutely need super unleaded and I agree. If you in doubt, try this. Have your spouse fill up your car and NOT tell you what fuel they used. Do this 3-4 times. See if you can tell the difference and / or guess which fuel they used. If you can't tell the difference, there is no difference.

I use the cheapest gas I can find in my Corvette. In tests we ran, the zero to 60 time was 1/10 of a second slower with regular when compared to super. Not much reason to pay 35-50 cents more per gallon.

Here's the difference. Regular burns fast, one molecule ignite ten and ten ignite a thousand and they ignite a million. The explosion is similar to a balloon popping. We measure the explosion in milli-seconds. Super burns slower, more like a someone letting a full balloon go and fly around the room. One molecule ignites 10, 10 ignite 20, and 20 ignite 30. Now don't start writing me and telling me I'm over simplifying this, I already know it!

So super, because it burns longer, should give you more power, better performance and better mpgs. However, the difference between the two different burn times may only be .2 to 1.2 milliseconds of time and I am quite sure no one I know can feel that. Yes, we can measure that on our dyno in 0-60 mph runs and other tests, but unless you can FEEL the difference, there is no difference.

Are there any other benefits to using super,
like cleaner injectors or a cleaner engine?

No. If you use the cheapest gas you can find, you will save lots of money and when you need to replace, repair, clean your injectors, you'll have plenty of $$ to do that. I can't tell you how many times I bid injector repairs (some as high as $1600 for 6 new injectors on a V-6 Nissan) and the customer says, "But I use super, doesn't that eliminate this repair?" and of course the answer is no.

Also see FAQ # 34 Pinging Problems

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