Just noticed the maintenance sticker on my newly purchased roadster in the upper left portion of the windshield. It states it was changed with 5w30 rather than the reccomended 0w40. Please advise!

 

I am no expert on this but I would not think it would be good to have an oil that misses the mark on both the low and top end.
As a minimum I would not try and use the car hard nor go the normal 7,000 miles between oil changes.

 

If where ever you purchased the car at-changed the oil as stated,take it back to them immediately and have the correct the problem.If not do it yourself.I would reccomend doing ASAP.Why chance it----------------Dave

 

Assuming it is Mobil1 5W-30 synthetic, then it is highly unlikely it will cause problems. However, the mfr recommended 0W-40 for a reason and that's what you should use. When I bought my SRT6, the dealer had used dinosaur 10W-30 and it had been test driven multiple times. I had him replace with the proper synthetic before taking ownership.

If cost was an issue, I would use Mobil1 5W-30 or 5W-40 in hot weather if it was cheaper than 0W-40 and my warranty expired. I would definitely use 0W-40 in a cold winter climate. That being said, I also decided that the $5-10 difference to buy 0W-40 was probably good insurance since I only change the oil annually and want the car to last.

 

As stated before climate has alot to do with it, 0-W flow characteristics are better for colder climates. Keep in mind these cars are manufactured in Europe where the climate seems to be much colder. Course couldn't bank on that being as I saw some -40's on the six o'clock news from N. Mich !!! Much too cold for my Texan blood !
5W-30 should not do any harm what so ever even tho it's not the recommended !

 

Great, thanks all for the feedback. I wonder if they DID use Mobile 1 or basic dino oil. However I'd have to lean towards the later. It's a used car lot I doubt they are going to invest in more expensive oil for a car they are trying to sell and make a quick profit on.

 

most mercedes dealerships switched to 5w since it was readily available and i think diesel mercedes were using that and only affects very cold climates. Do not worry about it run it hard or soft i think you will be fine and the next oil change use the 0w40.

 

0-40 helps with fuel mileage and start up viscosity. 5-30 wont hurt anything unless you live in the frozen north..

 

0W-40 only in mine.

 

The comments are pretty much spot on here.

Here is a snippet from how stuff works:
The viscosity grade (for example, 5W-30) tells you the oil's thickness, or viscosity. A thin oil has a lower number and flows more easily, while thick oils have a higher number and are more resistant to flow. Water has a very low viscosity -- it is thin and flows easily. Honey has a very high viscosity -- it is thick and gooey.

The net of all this is to stick with your oem requirements, however if you are a tad off with the 5w you will be fine for now but stay with the 0-40 as these cars were designed for the oil specified.

Thnx

Nate

 

Well I have used for years Rotella T Synthetic from Shell Oil (Wally Mart @ $20.00 / gal approx) -- 5W40 and have no worries at all. 0 weight or 5 weight -- come on!! -- pretty thin stuff and 40 weight with the engine up to temp and or in the summer -- seems about right.
Mobile 1 is good stuff and fine if money no object for oil changes and or if you are paranoid about a mfg recommendation and who knows what "deal" is behind all that !!

 

I guess this is as good of thread to ask this question as any.
Does anybody know if a "Chemical Test Strip" exists that you can simply dip it into a container of oil and it will automatically tell you if it's synthetic, or petroleum based?
Or does anybody know of a an "at home" test you can conduct to determine the type of oil you have?
Cross><Hair made a good point when he suggested the dealer may have put the "cheaper" grade of oil in his car.
I would't worry so much about the viscosity as much as I would worry about what type of oil they used.

 

Not sure of any home pregnancy type strips for oil but there are oil analysis labs you can send your oil to to get reports of additive strength, wear metals, how much oil life is left, etc...

 

Why risk it if you're not sure whether it's got synthetic oil or regular oil, particularly if you just purchased the car?

Take it in or DIY with the correct oil & filter - You'll sleep better.

 

Short answer is no..

 

To me oil is oil. I add over the mark and use heavier oil grade, cause I drive at the limit and buzz to 6k frequently. In summer higher weight thins and works well.

I also do an oil change every 5000 cause its easy 10,15,20,25...to remember.

Oil is for lube and COOLING of the motor. Turning .9+ g turns I like extra and add 1 Qt. The car does not complain. Rounding a turn once in an old chevy 2 the oil light came on and after checking it was not low, just stuck to the side of the oil pan.

My Challenger has 10 Qts and on start up two are stored in the trunk in a home made ACCUMULATOR cause it gets started only once and a while. Before I crank it up I open the trunk valve, feed two Qts into the motor and when the oil pressure gauge gets to about 20 psi, I hit the starter. Wet bearings are great for starting and longevity. Enjoy, Woody

Made it out of an old laser gas bottle, cut and welded to hold 2 qts at about 60-70 psi, self charging on startup............weeeeee

BTW the bungee is to keep the jack from ratteling.

 

Engines are built with certain clearances and the wight of the oil need to conform to those clearances. Oil acts like little ball bearings between the surfaces. As an engine get older these clearances start to increase and so you can extend the life of your engines by increasing the weigth. My engine has 61,000 miles on it and loves the 5w 40 Mobil One. 5w works great in cold weather, so since MB reccomends 0w I am assuming these engines are built with very tight clearances. If my engine still only had 7,000 miles I would still be using the 0w.

 

I think that LantanTX puts it right. Its not what we think we should use because oil is oil but rather how the engine is designed. The oil needs to lube the engine. That is its primay reason for beign in there and if it cannot get into all the spaces that it needs to lube (piston sidewalls and cylinder) you will have issues so too heavy an oil not enough lubrication and cooling. THe viscosity that we have heard about refers in laymans terms as "resistance to flow" and the higher the viscosity the higher the resistance to flow.

Shear and Time are also two elements that are considered when determing viscosity, and withoug getting into detail on these terms, simply know that oils have ratings for the precise reason that they differ for varied applications. THere is a bit of science behind the oil refining process. Oops did I just say that? Maybe thats why the world is fighting over it so much.. Sorry another discussion for another day

MB knows this engine and what works best in it. They do not want more warranty claims than they can shake a stick at so they tell you what they recommend. You engine is designed to precise tolerances and while there is definitely some latitude built into these designs, your car will work best following the engine oil recommended.

 

In addition to lubrication and cooling, oil also traps the dirty byproducts of combustion and carries them to the oil filter. Eventually the filter is full and the oil is dirty, hence the need for periodic changing.

There is NOT much difference between 0W and 5W Mobil1 for the type of driving most of us do. I suspect the big-*** sump of 8.5 qts barely gets warmed up if you drive short trips, so starting off with a lower viscosity oil helps distribute lubrication to the engine faster and prevents wear.

 

Your car comes from the factory with a quality synthetic oil. If they replaced it with standard oil, I would have it replaced asap. The filter doesn't have to be changed since it's fresh oil and it will drain down being that it is on top. Ah, the benefits of the filter being on top of the engine! Anyways, I'm in the Florida sun all year round and use one of the best out there, AMSOIL European Formula 5w-40.....