Filled my tank yesterday with good ol' regular gas at 2.17 a gallon, about 60 centavos less per than premium. Had about a quarter tank left of 93 when i filled it. Figgered I'd just drive it easier, as the TDI was off the road with an issue.
Well as the commute wore on I noticed that not only was there no pinging with the lower octane, but I noticed the head temps were almost 20 degrees cooler...
I'm not smart enough to know if this was related, or just that I was driving it easier. However, by the time I was nearly home (just before getting rear ended) I was back to thrashing it. I would swear it even ran better...

Is this possible?

Even switching to mid grade raised my idle. Must be the result of a more complete burn.

Not only possible, but possible. Test it on a full tank and report back...

Not sure, but here in ca,premium is 91 octane, I noticed your premium is 93.
Whats your regular octane?

Regular is 87, mid grade 89. Sunoco is the only station that carries 91 as an additional grade.

I've been told for years that regular is all we need for a stock engine. That's all I use on all my cars.

Are you not running a stock motor? Would think stock motor is fine with regular. Low compression.

Brett

Mmmm, left out that little tidbit, it's a 2056, 9:1, 9550 cam, Ljet.

You should probably be using mid-grade at 9:1

I don't think I have ever sprang for Premium fuel for my 914. 87 is what she gets and is very happy with it. The low compression of these motors does not require mid or premium.

The suggested "91 RON" is the European measurement for octane and is equivalent to our regular 87.

I ran my Squareback with regular for years with the 2056cc and never gave pings. The new motor though is another story. I tried mid grade with the last fill-up and she's not happy with me. Definitely a premium only engine; I already knew that, but I had to try it at least.

If you are running E10 regular it doesn't surprise me that it runs OK and cooler.
Ethanol is a cheap octane boost and burning it actually is cooler than gas, thus the cooler head temps.

That's the good.

The bad is it rots old fuel lines and carb diaphragms (any rubber bits), it attracts water (rusting tank bottoms), fuel mileage suffers slightly and it goes sour real fast.
Do not store anything with E10 in it, even with fuel stabilizer.

I use premium in my bug/914 because I set my engines CR to run on it and I use it in all my small engines, mainly because they are often stored for weeks with the same gas in it.
Here premium is ethanol free.

The wifes daily and my SUV, that get run all the time, I use regular E10.

Mark, all the fuels here on LI have 10% ethanol. No stations sell pure gas.

We have several stations here that sell pure gas, 87 nonethanol, purrrfect! It's 30 cents more than regular with ethanol , but still less that premium, which I have to put in the jag and the audi-tt.

Both of my d-jet 2.0Ls run slightly cooler on 87 than they do with premium.

Haven't tried to run my 1.7 or my 2056 on anything but 91+ due to them being higher compression.