Carlsson CLK LI

Hello gents, just a quick question regarding synthetic oil. I have only been using conventional motor oil for all my oil changes. my car has 28xxx miles on it and I want to give synthetic oil a try but I have heard that you needed to make the switch during the first oil change. Is it going to be ok to resume with synthetic when I have been using regular oil?
Thank you for your help.

Newbie

I'm pretty sure it's fine no matter when you put it in. I've been using it since day one.

Also, do you do your own oil changes? MB uses Mobil 1 synthetic (last I checked), and you don't?

Brian_R170

First of all, fully synthetic oil is REQUIRED in all US-spec M-B models with FSS, which includes all CLKs. MBUSA published this change in October 2000 and they sent letters to owners in the first quarter of 2001. So you should already be using synthetic oil.

Second, in general, it doesn't matter when you switch. There is some concern about switching from conventional to synthetic in engines that are both high mileage (>100K) and neglected. In this case the synthetic oil may appear to cause leaks, but in actuality, the synthetic oil just flows easier through existing holes.

The answer for you is to switch to synthetic ASAP.

Brian Yee

Not a problem. I've been switching cars from petro to synthetic since 1976. Brian is right; It does have a tendency to flow more easily than petro based oils, so if you have a leak, it WILL exacerbate the issue....Small spot gets bigger so beware. Small price to pay for the advanced protection.

Carlsson CLK LI

Thanks for the advise, I will make the switch to synthetic at my next oil change. Regarding newbies question, I do not go to MB for my oil changes so I wouldn't know what they recommend. Personally I don't feel like bringing my car in for an oil change, waiting as they work on 20 other cars before mine then go to lunch just before they get to me. My MB dealership is not the best in terms of expeditious completion on work of any kind. I know of much better ways to waste an entire day. Not to mention, at the end of that day long wait, I still have to pay double for an oil change I could have had done at jify lube with the same oil.

Not bitter or cheap, just can't stand to wait!!!

Newbie

Well I don't encourage anyone to go to MB for regular oil changes, but if you've got FSS they should be doing the oil change when you get your car serviced. I change my oil inbetween FSS services and I definitely don't pay MB's ridiculous prices when I do.