htc280

I wanted to know if 89 gas is fine for my 94 c280. On the gas cap it says premium gas only. I have been putting 91 gas in it but would a 89 be okay.

davis449

This topic has been beaten to death, but you should always use the factory reccommended gasoline grade. Some people have run 87 with no problem, me personally, I ran 87 once and my car stalled and ran like ****.

GDawgC220

I've used 89 before and car felt fine (c220). Didn't notice any difference in MPG either. short term shouldn't cause problems, long term tho, who knows.

pocholin

There's a reason they say Premium recommended, if you own a Benz you should pay the price, get a chevy or a honda and you'll be perfectly fine using 87 or 89. besides if you really think about it and do the math you'll only be saving about $ 2.70 (at the most) per 18 gallon fill up at the risk of long term injury to your engine, knocking, less mpg, etc (all of this is just the risk).......my 2 cents

!!!!!NJ Drive

I was just about to make a thread kinda like this...Iwas at the gas station filling up & told the guy (who was talking on his mobile phone) fill it up premium. When I hear the hose click turn around to find out he put in plus (mid-grade~89) I got the guys name spoke to the manager & told him he put in the wrong thing & if any thing happens that they are responsible..they both had a look on their faces like "yeah righ".

I was at a little more than 1/4 of a tank, havent noticed any problems except there seems to be a strange smell in the inside...i didnt notice until 2 days later, dont know if its related

RunInColorado

There was a Car And Driver article a year or so ago that detailed whether using a different grade of fuel really matter. They tested a mustang, a M3 and maybe a couple other cars (this is based on my memory recall so dont quote me on it). They found that for cars that are made for premium using a lesser grade only hurts performance a little bit but had no comment whether it hurt the engine or anything else. They also said that if you run a car made for just regular unleaded on premium little if any power gain results.

There was also a CarTalk episode dealing with the same issues and they stated that the altitude of where you live has an impact on rating of the fuel. For example, if you live in Denver (elevation 5'280 ft give or take a little) you could use a lower octane rating without any bad effects.

I think I could find the Car and Driver article if anyone is interested, although I am not sure about the CarTalk, but I could try.

I hope this helps.

Benz916

I remember that article too..the car and driver one. I think I have the subscription laying around here in my pile. I'll check to see .

eddieo45

I agree; except my tank is 16 gallons. I use 93, as my choices are usually 93, 89, or 87. Performance is great, but I wish I had better mileage (can't imagine it would come with cheaper gas)

MikeL

I've never put anything else in my car except for premium gas. I remember reading the manual, it says premium fuel only and if you have no choice but to put in lower grade, it specifically says only put in a minimal amount, just enough to get you to a another station with premium. And also says not to exceed like 3000 rpm when you have ****ty gas in the car. The difference between filling up regular and premium is minimal anyways, only several dollars difference.

pocholin

I read the article at car and driver, if anybody is interested just do a search at C&D

They didn't go much into the carbon accumulation, that long term can yield to much loss of power and efficiency (mpg), plus the risk of detonation and knocking, which in new cars is not a big deal because of the knock sensors but then again if the computer detects knocking it is going to reduce your engine's output which translates into less HP/less performance (retard timing).

I guess people buying a new/good car should be willing to pay the price to maintain a fine automobile, and this doesn't just apply to gas, but brakes, oil changes, and other routine maintenance items.