tarheel76

I have a 2004 with 58k miles and my indy MB shop put in Mobil1 10-30 at the last change. I live in Eastern NC and I only put about 6k on it per year. Should the shop have used 5-20 or 0-30 synthetic in it? Wally World has the best prices on synthetics. How about Castrols synthetic has anyone had any experience with it.

tarheel76

RichardM98

MB recommends 0W-40 for all CONUS driving. If you want to use a factory approved oil be sure the container says "MB Spec 229.5" One such oil commonly available is Mobil 1 fully synthetic 0W-40 (European Car Formula). There are Castrol oils which are also factory approved.

saintz

Your 2004 is actually a W211, and this is the W210 forum. Doesn't matter in terms of oil, but just for future reference.

0W40 Mobil 1 is the best bet. 10W30 is an inferior oil, and it's not recommended. Castrol and some other brands may have approved oils, but anything MB approved will cost more than Mobil 1 0W40 (and won't be any better) so there's no reason to look at anything else.

The fact that your MB indy used 10W30 is a little worrisome. They should know better and they shouldn't cheap out.

You most likely can't find the 0W40 at Walmart. It will cost a few bucks more at an auto store, but there's a reason they sell 10W30 in bulk at Walmart but you have to pay full price for 0W40: it's better. Some people think it's "close" because 0W40 is similar to 5W30 if you simply look at the numbers. But the additive package is totally different, and the oil is simply better and more expensive.

It won't blow up your engine, per se, but I would have a talk with your shop, and at least at the next change, pay the few bucks for the proper oil. I would probably change at 5k or 7k miles instead of the normal 10k if you're running out of spec oil this one time.

tarheel76

Thanks for addressing my question even though I was in the wrong forum. The oil container says Mobil 1 Fully Synthetic 10W-30 but I can't find anything like MB Spec 229.5. I thought that all Mobil 1 Synthetic was of the same quality. This is the first MB that I've used synthetic in so I've got a learning curve in "Oils 101". You mentioned that MB recommends 0-40 for all "CONUS" driving. Please explain "CONUS" to me. In the mean time I'll check with my indy shop concerning the oil they used in my car because a majority of their service is to high end cars. Thanks again....

tarheel76

RichardM98

Modern oil is a mixture of additives besides the basic lubricant. MB has a specification and oil companies are free to prove that meet it or pass. The spec oil will be the factory fill and the recommended replacement.

CONUS = Continental United States In the 'old days' people changed viscosity of straight weight oils depending on the seasons or climate. With modern synthetics that's not necessary.

As mentioned, nothing is going to blow up. But it important if you wish to use the cars computer to determine oil change service cycles. It's also important to use a 'fleece' media filter so you might ask your indy about that as well.

saintz

When Mobil 1 first came out, it was about the most expensive oil you could buy at the store. Now, it's generally the cheapest synthetic on the market. My understanding is that they reformulated most of the Mobil 1 weights to be less expensive in order to better compete. This meant using cheaper additive packages, generally. They apparently kept the 0W40 formulation, however. Hence why this weight is generally not available in 5 quart jugs at Walmart and why it costs more. And why Porsche, MB, VW, and others specify the 0W40 exclusively.

Also, the wider the numerical distance between the two weights, the more versatile the oil. 0W40 can work across a wider temperature range than 5W30. This temperature range, plus the additive package, makes it a better oil.