Quick Q: '87 190 2.3 ... Regular or premium?
 

I am trying to determine which fuel grade for my daughter's '87 190 2.3: Regular or Premium?

Thank you in advance,

Haasman

I run premium because it's recommended by MB.

No fuel-related problems yet, but that may not have anything to do with octane quality.

If ever I do have a fuel-related issue, at least it's a parameter I can rule out.

Many on this forum used regular (81-85) and have had good results.

Higher octane fuels have a higher "flash point" i.e., needs higher temps in order to ignite. So there is less of an issue with problems such as "pre-ignition" or detonation.

But if you start hearing pinging under load conditions, then you do need to bump up the octane choice.

I have a 190e 2.6 and use mid-grade. Regular octane gas can really affect starting conditions when it's very cold outside. I've found it less problematic with the mid-grade.

I used preimium when I first bought the car, and it didn't run so great. MUCH better with mid-grade.

Thanks for the input!

Haasman