your car will last longer... thats a point

 

It's not just about gas mileage. You shouldn't notice any differences until you've ran a couple gas tanks through with premium. After that you should notice a few mpg gain, but not that much. These are German cars and require premium, especially if you have the 1.8T. Things run smoother and the engine will last longer.

 

Other factors that come into play for higher octane gas are, driving style, compression ratio, chip/tuning, turbocharged...

The best way to determine how YOUR car will perform with YOUR driving style on a particular type of gas is to try it and see.

When the car manufacturer suggests higher octane it's because the car is set up to use higher octane. In these types of engines, lower octane gas is more likely to detonate. If you run lower octane the engine management systems will compensate to the extent they can by pulling timing, changing A/F ratio, limiting boost... The main thing you want to avoid is detonation. Detonation will kill an engine in the long run.

As an example, years ago in a 77 Nova, I burnt holes in two pistons of a Chevy 6L because of detonation. This forced me to swap in a semi-built small block V8. :thumbup:

 

I've done long-term tests (5-10 tanks, all throughout the year) with both 87 and 93 in the V6. A couple other members have done the same.

No difference in economy whatsoever. However, I do feel a very slight smoothness improvement using 93 under hard acceleration. But for daily driving, the $.20 to $.50 savings per gallon were a fair tradeoff for something I didn't need.

If anyone can run at least three tanks of each and come up with more than an inconsequential 0.5mpg difference, I'll be shocked.

 

I knew I would take some heat on the topic and I agree that the detonation is a factor but I'm going to ask a DUMB question.

What happens to an engine in the long run if one continues to use the lower octane gas?

 

Burnt valves and carbon build up.

 

Since you're the first person I've ever heard say anything like this, I'm going to have to ask for some reading materials. It's hard for me to fathom how 90% of drivers out there are killing their cars with 87 octane.

 

:banghead: For 99.9% of drivers 99.9% of the time with the V-6 you will not see any difference with 87 octane you will not see any MPG difference ! I am done with this topic and I will not be responding to any comments, I am gonna go for a drive in my V-6 using midgrade 89 octane :driving:

 

For 99.9% of drivers 99.9% of the time with the V-6 you will not see any difference with 87 octane you will not see any MPG difference ! I am done with this topic and I will not be responding to any comments, I am gonna go for a drive in my V-6 using midgrade 89 octane

haha im with you on that one brother, but at some gas station i was at, i put in mid grade and looked at the little counter and they only had to options, "low" and "high" grade counters but they had the mid grade gas, so i wasnt sure wtf was going on but it was too late