Hi,

I recently bought a used 97 SL500, and I was wondering if anyone knew where the performance chip is located, and whether I can identify whether it is OEM or aftermarket. The reason is that I noticed that the muffler tip is not OEM, and I think the muffler system itself could be aftermarket (because it's louder than the usual). In which case, this owner might have invested in an aftermarket chip, and therefore I should NOT be putting in lower octane fuel.... :p

Thanks!

Your M119 engine should be running on premium unleaded even without a chip. You can run it at lower octane levels without significant damage (thanks to the knock sensor), but you'll be losing power.

Troy
1995 E420 86k

are you kidding me? it says premium unleaded only right under the fuel gauge. heres a tip... read your manual. there is a reason that car cost so much when it was brand new.

icetrey, why don't you read my post carefully? I asked for the location of the chip, not cynicism.

Thanks y2kimmel, I've been mixing 91 & 87 as some threads here have suggested. But I still need to know if I have an OEM or aftermarket chip, because the aftermarket would disable the knock sensor. At least with the OEM chip, I can run the 91/87 cocktail and know that if there is any preignition, the knock sensors would do its thing....

reading carefully you say... well, i was refering to your use of low octane gas... didnt have anything to do with your chip. anyways, what does it matter if you have a chip if you insist on putting cheap gas in your car? you buy a benz (which is a luxury car) and then you put cheap gas in it... kinda like ordering fillet mignon and covering it with ketchup.

When it comes to gas, expensive does NOT equal better! Now, the engine may require higher octane gas, but the concept of calling higher octane 'premium' is purely a marketing idea designed to trick people into thinking they are putting 'better' gas into their engine. Higher octane just means it burns at a higher temperature, not that it makes more power, or is cleaner, or better, or anything. My friend's race team runs 87 octane because thats the way they tune their engines, low compression and EGTs w/ high volume. Your argument that it is an expensive car and hence needs expensive gas makes no sense. Choose the octane that is best for the engine's design, whether that is cheap or expensive, that will be the best gas for the car.

That said, the engine may need the higher octane based on higher compression. I don't know exactly where the chip is on the engine, so I can't advise there. Can't you ask the PO? Or are they long gone? If you can't find out, you can always run 91, which is a good middle of the road octane.

Peace,
Sam

__________________
"That f***in' biodiesel is makin' me hungry."

1982 300TD Astral Silver w/ 250k (BIO BNZ)
2001 Aprilia SR50 Corsa Red w/ 5.5k (>100 MPG)

You're pretty quick to jump down someone's throat when you think they might be wrong, but you're certainly not willing to listen to anyone else. Sheesh, with less than a dozen posts you're already pissing off a half dozen people? Are you 12 years old?

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John Shellenberg
1998 C230 "Black Betty" 240K

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