Today when I went to refuel my car, there was a newbie who gave me Regular Plus (89octane) when I actually asked for Supreme Plue(94 Octane)..(it was a full service gas station)..I immediately stopped him when I notice and fill the rest of the tank with the Supreme Plus. Now the question is, would the mix of gas damage my car, especially its engine? I drove a '99 C280....any input is appreciated. Thank you

I am not a mech. but you will be fine. For a piece of mind if you have any knocking, just add a little octane booster.

Have a pint of premium beer and you would have thought your tank was full of premium fuel.

Relax, bro ... :)

Or worse - a station jockey put diesel into my dad's MB coupe a number of years ago - very unhappy gasoline engine!

Wow - if that was diesel that went into your petrol tank, SKY, drink lots of premium beer coz you're gonna have a big headache whichever way you gonna think.

Look at it from another angle, it could have been diesel instead of Regular fuel ... :)

ps. This reminded me of my friend's daughter who had the liberty to drive his car one weekend. Thinking she was doing her dad a favour by filling 'er up, she went to the kiosk and was confronted with 3 choices : premium, regular, and diesel.

As this was her first time doing a fill-er-up, and its self-service, she thought that the fuel marked "diesel" was on sale!

No second guesses why:
1. she learnt which fuel to use;
2. the car refused to start (lucky it wasnt the other way round 'wise the car would have been blown to bits);
3. she was grounded till she knew how to maintain a car, which includes filling it with THE RIGHT fuel, and checking for the essential fluids;
4. her dad was mad; and
5. had his mechanic was laughing all the way to the bank.

pps. so SKY, it aint that bad. :)

[Edited by ymsin on 03-09-2001 at 06:44 AM]

Ok thanx guys...the tank filled with half regular plus really reduced the performance of the car. The car feels like it is heavier and harder to acclerate than before. Oh well I guess I have to "easy" drive it until the next refill. At the time of refill, my friend was with me, they said I should have ask the gas station manager or supervisor to come out and tell him about what the pumping jockey did...this way they will get some kind of punishment...but I didn't ..somehow I wish I had did so though...:D

Virtually all engine controls on MB engines of the last fifteen years or so include a knock sensor that will retard timing when spark knock is sensed.

Although I would not recommend it, you could run regular all the time without doing permanent damage to the engine. Because of the automatic adjustments made to timing and other parameters, power and fuel mileage would suffer if you did this.

My recommendation is to run it to about 1/4 tank, fill with premium and forget it. There will be no harm done.

Have a nice weekend,

I'll second LarryBible's post.

A few times I deliberately put Regular in my Audi (because it was cheaper) even though it has a Premium on the fuel door.

Nothing happened. :confused:

Well, performance did suffer a bit, probably a result of the knock sensor retarding the timing. I never heard any pinging, so the sensor was doing its job.

Go out and cruise around until you need another tank full and fill 'er up with Premium.

BCingU, Jim