What gas to put in a'87 560SL - PeachParts Mercedes-Benz Forum

mybaby · #1 08-10-2006, 09:57 AM

Need some advice please on what octane level I should be using in my '87 560SL (45,000 miles). I ask because for the first time I put 93 Octane from a no-name gas station (dumb move I think) and the following morning, the car was not performing good. When idle, it sputters. At higher speeds, it is OK. Being that I just had the car serviced and all is fine, that is why I am questioning the gas. I'm thinking if I burn the gas off and then put in a lower Octane mix, I might be OK. Any advice is greatly appreciated!!! New to this forum so any quidance would be great.

Jim B. · #2 08-10-2006, 10:13 AM

The 560 motor requires premium fuel, per the Mercedes owner manual that came with the car.

I have put ONLY Chevron Supreme (premium) which comes with the techron additive, in the my 560SEC car for the past 10 years, and NEVER had any performance problems with the engine.

The Chevron premium with techron is supposed to keep the injectors clean.
I actually think it is true, even though I get no joy paying the higher price for the premium gas. The 560 engine was the top of the line motor for the very expensive Mercedes models, it was assumed by MB that therefore the cost of fueling them would not be a concern to the owners who could afford to buy these cars new, in the first place.

I replaced the injectors at 100,000 miles as a preventative maintainence ploy and now, with tuneups at each 30k or so, everything is still fine at 118,000

Stay away from cheap gas and no name stations for a 560. Low octane gas could cause pinging, and some of the no name gas stations have inferior gas, or storage tanks almost empty which could suck up rust flakes into your car and cause mischief.

mybaby · #3 08-10-2006, 10:34 AM

Chevron still around? Don't think I've seen one of those stations in my neck of the woods (NJ) in a long time. What brand would you say is comprable and reputable? And yes, according to the manual, it states 91 or higher. Ironic though that as soon as I filled the tank with this no-name gas, the problems started. Do you think I am doing any damage by driving the car with this sputtering? And would you advise burning off the fuel and at around 1/2 tank, giving it some brand-name gas? My "other car" is Durango with a Hemi so I've blocked out gas prices...at least it my mind. Wallet is definetly a little lighter though!

I thank you for your advice and quick response.

Jim B. · #4 08-10-2006, 10:49 AM

By the way, welcome to the forum, it's a great place for answers-and questions too, so since I'm on the West Coast, I don't know the equivalent best gasoline, for the 560SL, but I'm certain someone else will chime in.

If I were in your shoes right now, I'd bite the bullet and fill up with Premium gas, and hope it diluted the "bad" gas you got. If there were still problems with stumbling and so forth, after that, I would probably suspect I now had a fuel delivery problem, and maybe change the fuel filter, or think about the fuel line....

I'm sorry this happened. The 560 is a very good engine, though if driven with verve it will have OPEC-busting thirst.

At only 45k miles it's barely broken in. With highway driving it will go 30k miles between tuneups, and coolant changes. Don't have to change the timing chhain, tensioners and guide rails, and plug wires (Beru are good plug wires) till you hit 100k.

These cars are not especially cheap to care for, but OTOH they are actually quite straightforward to work on, so if you have a good Independent mechanic or can DIY it should not be too dear to keep. I would, if possible, avoid the cufflinked/white glove Mercedes main dealers.

Dee8go · #5 08-10-2006, 11:16 AM

I use premium (>92) gas in my cars, but have read many places that you should use the lowest octane you can that doesn't cause engine knock. I just try and follow the manufacturer's recommendations.

This raises a question for me, though. What is engine knock? What is the relationship between it and octane? Anybody know?

SunGuy · #6 08-10-2006, 01:05 PM

Quote:

Originally Posted by mybaby

Need some advice please on what octane level I should be using in my '87 560SL (45,000 miles). I ask because for the first time I put 93 Octane from a no-name gas station (dumb move I think) and the following morning, the car was not performing good. When idle, it sputters. At higher speeds, it is OK. Being that I just had the car serviced and all is fine, that is why I am questioning the gas. I'm thinking if I burn the gas off and then put in a lower Octane mix, I might be OK. Any advice is greatly appreciated!!! New to this forum so any quidance would be great.

Premium fuel only, peiod. If your engine is sputtering at idle, it could be dirt/rust from the dispensing tank at the station. Pick up a bottle of Techron or Lucas Injector cleaner at Autozone or PepBoys and put it in your gas tank when 1/2 - 3/4 full. AND/OR, it could also be water in the gas that also came from the dispensing tank. I've used a product called HEET, which is some form of alcohol that evaporates the water and burns off with the gas when it goes through the engine. I've also used both products simultaneously in my 560SL without incident. After you have that stuff in there take the car to parkway/turnpike and run it. After 10 minutes your problem should be cleared + it's a good excuse for a ride.

If Chevron is hard to find, I've also used BP/Amoco which you've got plenty of in NJ-

Bob

mybaby · #7 08-10-2006, 03:40 PM

Any excuse for a ride. Rid myself of the hubby and the children. Perfect! Thanks for the advice. I will be trying your cocktail suggestion this weekend when the weather is suppose to be ideal.

iwrock · #8 08-10-2006, 05:02 PM

My dad always tries to run either 76 or Chevron in the 600. It just burns better, and it just idles smoother on it. I know that the 76 burns faster than the Chevron gas does, and it feels that much more peppier when it has 76 in it.