Back on November 22, 2010, I decided to start a test using 87 octane gasoline instead of the recommended 92 octane gasoline like the owners manual states.

The original plan was to test with 5 fill ups using 87 octane gasoline.  I ended up testing with 8 fill ups.

The different between the gas mileage while using 92 octane gasoline and 87 octane gasoline is almost unnoticable.

So, I fill up with 87 octane gasoline now instead of 92 octane gasoline.

The first thing that I noticed with 87 octane gas in the tank is the amount of pep the vehicle has.

I have also noticed that the engine is eating more gas as the gas gauge is going down much faster than it does when 92 is in it.

The Tiguan owners manual recommends higher octane gasoline.

I have been putting 92 (93 when available) in ever since I got it.

I had to gas up today and decided to do a little test with 87 octane gas.

I will gas up the next 5 times with 87 octane gas to see if the gas mileage takes a hit.

You can follow the results on the Gas Mileage page.