15W40 Vs. 10W40 Pro's/Con's, Which ones BETTER?
 

Hey guys, I have a question that not even the dealer could give me an answer for, just simply put they said use 15W40.

Now what do you guys think is a better choice to use on a 94 C220?
10W40 or 15W40?

Now 15W40 Castrol say's, Diesel oil on it while on the back it says it meets Mercedes standards. Mean while 10W40 costs a few dollars more, yet fails to mention any mercedes standards it meets, yet it drops the "diesel oil" label. So my question is, isn't 10W40 better for the car? How do these oils line up, the pro's and con's againest each other? which ones a better choice strictly for mercedes?

I want to get an answer on this one.

THanks

15w40 "diesel" oils tend to have more additives (like zinc) as well as more detergents. That's what makes them better. The 15w40 oils seem to make all Mercedes -- gas or diesel -- a little happier. :)

Down here, however, my 450SL prefers 20w50. It tends to find ways to leak 15w40 more readily in the heat! :cool:

which one provides better heat protection? and also why is 10W40 more cash?

They're both going to be fine, stop worrying about it, just put some oil in the car. There's virtually nothing you could that would have any impact on the life of the engine.

Neither one is "better" than the other. The different weight oils are designed for different tempature ranges and different engine requirements. Some cars need heavy oils and some need thinner ones. Also different envorimental issues may affect which oil you should use. You would not use the same oil for a car that spends most of its life in Minnesota as you would that spends its life in Miami.

If you look in the back of the Mercedes Manual for your car you will notice that all of the approved oils for your engine are listed. It will also show a tempature range that the oils are good for. The best oil will be the oil that best fits the tempatures that you might see in your paticular climate.

I use Mobil 1 in my car with a weight that varies depending on the season. I use the chart in my manual to determine the weight.

In general...
 

...a 15W-40 HDEO (heavy duty engine oil) is more shear resistant than a typical 10W-40 PCO (passenger car oil) because the viscosity spread is less (there is less need for additives to extend/maintain the viscosity range).

HDEO's typically are both diesel & gas certified (i.e. CH4/SL) and are often an excellent choice for cleaning an engine (or keeping a clean engine clean). They often deal better with heat and longer oil change intervals.

For the premium price paid, typically $6-7 per gallon for dino HDEO's (Pennzoil LongLife, Delo 400, Rotella-T), these oils are usually considered superior (for older MB's at least) than typical dino passenger car 10W-40 oils (Quaker State, Valvoline, etc.) by many. There are some excellent dino oils but not as many in the 10W-40 weight (vs. 10W-30).

As indicated above, temperature range is a very important consideration. Most HDEO's are fine year-round except in very cold climates. Some 100%Synthetic HDEO's (Amsoil AME 15W-40, Rotella-T Synthetic 5W-40) are reliable down to some pretty cold temperature ranges.

Try the SEARCH for 100+ oil threads.

Cheers!

If it were in my stable it would be getting 0w40 but thats just me. 15w40 must be real fun in winter up their. I ran it in my SD and when the temps fell into the single digits it was like sludge. Good thing for a strong starter!:D

See the thing is it's not in the back of my manual. My manual mentions nothing about oil, other then checking it and making sure its fine. The chart you're talking about I have seen in my wife's car's user manual, but that's for a jetta. So I found it strange that Mercedes would recommend a diesel oil which I have always used on my gasoline car versus the 10W40 version which is intended for gasoline car's. That part I find a little strange, as people at part shops in the past have questioned me using 15W40 in a gas powered car....

Figure out what MB specs for your C220, 229.XX.
http://www.whnet.com/4x4/oil.html

Their you go right from the source.

Hey thanks for the breakdown. I'm just surprised that mercedes would recommend a diesel oil for their gasoline car's where as the 10W40 is a oil for gas engines. 10W40 however is never marked as meeting mercedes spec's on castrol bottles as the 15W40 is. So I find it strange that while 10W40 can be used, why its not recommended. Here in canada 10W40 is alot more common and availble in more brands then 15W40, however the 15W40 is much cheaper. So that's where I begin to wonder what the advatages of using either one are.

Thanks for you're response

It may be in a service booklet thats seperate from the actual manual. I don't remember exactly. I remember looking it up recently on my 1999 S320 for its first oil change.

Hey man. Actually our winters in Vancouver are similar to seattle and are very mild and warm. It doesn't get near freezing or snow here ever, its actually pretty mild throughout the winters just a bunch of rain. It never gets anywhere as cold as CT. here, but other parts of canada can make CT look like Hawaii in the winter. Even with these mild winters, if I don't park my car over night in the garage, the 15W40 isn't quick to warm up and smooth it self out. COnsidering 15W40 is a mercedes canadian spec, it amazes me that other places in canada that are much colder must be using the same oil and surprised they havn't switched to the softer 10W40. I think mercedes is using the 15W40 oil just for longer intervals.

If its synthetic like Amsoil run it 6k miles and have Blackstone test it. You may be able to go even longer. Typically with lots of highway use we can run about 7k on our old diesels.

are you Doug Ely?

No?:confused: Why do you know him?