W124 Oil Types

[krjt]

Any one using Castrol Hi Mileage or Valvoline Hi Mileage 20-50?
I have been using Castrol GTX 20-50 and wondered if the above two oil is recommended by others or Merc. Does it help with oil consumption?

Thanks.

I would not run an oil that heavy, but if you are having major consumption issues it might be worth a shot.

20-50 in my M119 would be a quick prescription for a nice lifter tick.

[tilac1]

My '88 300E has only 40K miles and uses a little oil but I tried the Castrol Hi-Mileage and it stopped leaking. I went back to GTX and the leak returned.

[antonino]

I own a 91 300 Ce that is a 124 and use Valvoline high milage oil in several of my vehicles. However, the 20-50 you are using is too thick an oil for this car...you should be using no more than 10W40...good luck.

Antonino

[deanyel]

Those oils are both fine. The proper viscosity is a function of where you are. 20-50 would be fine now if you are in the southern hemisphere in a warm climate. If you are in the northern hemispere you really shouldn't be using 20-50 this time of year - only in the summer in a warmer climate.

[Hatterasguy]

Don't know what engine you have in your W124, but if its a later model its an M104. My friend has been using Mobil 1 0w40 in the M104 in his S320, works well.

[cummins]

I run 15-40 with slick 50 in my 300E and it runs fine. The 20-50 is too thick unless you have major consumption with thinner oils.

[WANT '71 280SEL]

Supposedly the PO used Mobil 1 0-40 in my S320 as well. I would think a 40 weight is the thickest you'd want to go in such a car.

Thanks
David

[Hatterasguy]

Yeah 50wt is more of a racing oil.

[krjt]

For whatever reason, I thought 20/50 was a good weight for summer and 10/40 was winter stuff. As I live in the San Francisco Bay, where the climate is mild unless I drive into the valley, I thought it was ok... looks like I need to rethink the 20/50.

Thanks.

[Xsbank]

My understanding is that the '20' is the viscosity of the base oil and the '50' is the virtual viscosity arrived at by the addition of additives and processing. Therefore the '50' is the viscosity that is effective with the engine hot and the '20' is the cold-start viscosity.

Now you've got me all exercised - I'm going to have to look it up!

[Hatterasguy]

Originally Posted by krjt

For whatever reason, I thought 20/50 was a good weight for summer and 10/40 was winter stuff. As I live in the San Francisco Bay, where the climate is mild unless I drive into the valley, I thought it was ok... looks like I need to rethink the 20/50.

Thanks.

SF bay is mild all year. Just run a 5w40, no need for winter or summer oil's anymore.