Can I used 89 Octane gas in my 97 E420?

[cabby850]

Hi,

I know MB recommends premium fuel for the e class, but has anyone used 89 octane gas and got away with it without any problem?

what kind of damage can I do to the engine if I used 89 instead of 93?

Thanks

Ed

[SaMaS]

I would advice you , DON'T GO CHEAP ! Save a $0.15 spend $ 4000 ... just my opinion, best luck to you !

[Raylee177]

SaMas has given you correct advice. I recommend that you follow the recommendation.

[gregs210]

This is a recurring question, here's a recent thread post with my response suggesting you shouldn't do so (which I didn't want to retype here): http://forums.benzworld.org/forums/forums/thread-view.asp?tid=1224960

Take care and enjoy the ride,
Greg

[mjhawkins2346]

Sure, you can use it. The engine will compensate the best it can by retarding the spark.

You will lose some power, the engine will run hotter and with less power and your economy will suffer. If it can't retard the spark sufficiently, you will get pre-detonation (knock) which can be very damaging to pistons.

If you have any warranty to be concerned about -- it could affect coverage if the low octane fuel causes damage.

In the end, I would do it carefully as a stop-gap and not get into this habit.

The money you save at the pump will be taken away in fuel economy. Run the experiment yourself if you're not convinced[:0]