intrinsico

Folks,

I was in a rush at the gas station and didn't notice that I selected regular gas... I only pumped like 6 gallons and then switched to premium (for another 12). I panicked so I also poured in one of those ATP fuel cleaners...

Can someone elaborate on the obvious question "what did I mess up?". I also had to bring the car in to the dealer (to have my aftermarket xenons progammed) and I noticed some rough idling so I mentioned it to them. They said that "something is misfiring in there" so they'll look I can't remember if that started before or after pumping the gas but hopefully it's not related to the gas issues.

Any comments, suggestions would be highly appreciated.

Thanks guys,
Sergiu

DWP

It wouldn't do any damage even if you had filled the tank all the way with regular gas (which is 87 octane in California). The worst that would have happened is a reduction in power and a decrease in mileage. Modern cars like the W211 have engine management systems that prevent pre-detonation (knocking and pinging) with lower-octane gas. Don't worry about it.

Brav

you're cool. nothing will happen except you saved $2.70

intrinsico

Cool, thanks a lot for the quick replies!

HELL ONA HARLEY

As the others have mentioned, don't sweat it.... The only thing I see you did wrong was to put that additive (fuel cleaner) in the car... This may be the cause of the reported mis firing

MBE55AMG

I can buy 3 Arizona Iced Teas with that amount!

intrinsico

Now, let's say the additive caused the misfiring. Would this go away when I fill it up? The normal premium gas here is 93 but Sunoco also sells a 94. Should I fill up with that for a couple of tanks just to get things back to normal?

JimPurdy

91 octane is sufficient - the 94 octane Sunoco shouldn't make any improvement. A couple of tankfulls of fresh fuel should flush out all of the additive.

SAguirre

The manual states that it is OK to put regular fuel in the car if you have NO CHOICE. It states that if you do put regular fuel in the car not to rev the engine high and treat it as if it on a race track. I have not put regular fuel on this car yet, but on occasion, I have had to put the cheap stuff in my other Mercedes cars. I never drove them hard and the cars ran perfectly. As soon as I could, I put premium in the car again and that was all.

The problem here is that people assume that cheap gas in DIRTY. If you buy low-octane gas at a reputable station it will be just as clean as the premium fuel. Fuel grades are referring to the octane rating, not the cleanliness of the fuel.

At the same time, there are very few fuel injector cleaners that Mercedes Benz approves for use in their vehicles. I have never put anything other than 44k in my cars. I have had really bad experiences with other brands in the distant past. Some people even report having fuel gaskets and injector damage from some cleaners. You hopefully will not have any permanent negative effects of the cleaner, but I would be willing to bet that the missing/misfiring is from the injector cleaner and not the cheap gas.

There should be no damage from the occasional cheap gas use as long as you don't give the car hell when it has cheap gas. I always get premium, but only if I can not help it I sometimes get whatever the place sells.



Good luck,

Steve

Brav

The only diff is that premium has some additives that the lower grades don't have, eg, "Techron" - whatever thats really worth.

Brian_I.

I put an additive in my CLK once and the next day the Check Engine light came on and one of the O2 sensors went out.

ddrango

So i can put regular gas in my 03' E320? I'm in NYC and regular is 83 or something. What would happen? I have mine leased until march next year.

intrinsico

Ok, update on the rough idling: service advisor said it was due to a bad spark plug wire and they just changed them all (seems like that's what they do these days, they roughly diagnose a problem and then change everything that could cause it). Anyway, still seems rough to me so I'll take it back... They said it's not normal and they don't know what would cause this. I'll keep pumping the premium gas, hopefully once the additive is gone from the system everything will be alright.

SAguirre

Mercedes only says you can for short periods of time and when you have no choice. Otherwise, you should use at least 91 RON Octane.

Your question here reminds me why I don't even consider lease returns if I had to buy a used car. I am sure that you are not the only one who is contemplating or doing this. Prolonged use of cheap gas would probably do some damage to the engine like excess carbon deposits and stuff. This is penny wise and Dollar foolish.

Steve

tuscanraider

If its a lease, why not use regular? I lease my C, and I make sure to bang the RPM needle off redline as often as I can. This is one of the perks of leasing. Since its an '03 even the service is included.

Brunelleschi

The man has a point

glojo

I hope your service advisor does not make an issue of you putting in the 'cleaner'. It sounds like there is indeed a problem which needs to be sorted.

Good luck,
John

Brav

83?? thats like putting in fire retardant. Should be at least 87 for regular. Thats low..

JimPurdy

83 octane? As a friend of mine would say; "That Aint Even Horse Pi$$".

ATS

I put Sunoco 93 Octane in.. Is there any point? Anyone else put this gas in as well? I own the car and plan on keeping it for at least 10 years..