Hi all,
I was just browsing the local auto centre and noticed that Mobil1 has a 5w50 synthetic. Any thoughts on this weight? The range seems fairly wide.

 

I wouldn't use it... just curious, are you thinking about using it? if so, why do you think you need something that high? is 20 or 30 not enough to provide the lubrication/protection that your engine needs?

 

I don't plan to use it though. It is for my other car - saab 92x aero. I use 5w30 M1 synth. But this 5w50 peaked my interest.

 

Multi-weight oils are obtained by adding viscosity modifiers to the base oil. Those ingredients thicken when hot so you get an oil that is pourable at cold temp but still keeps viscosity at higher temps.

There are 2 drawbacks. One is, the viscosity modifiers replace some of the oil that would otherwise be providing lubrication. The other is that the modifiers "wear out" over time and so you end up with a thinner oil.

Not to say that you should use a straight-weight oil. But extreme ranges like 5w-50 require a LOT of modifiers. You're probably better off with a narrower range like 5W30, 10W30, or 5W20 depending on your weather and requirements. If think you really need a 5w in winter and a 50w in summer, maybe run 5W20 in winter and 20W50 in summer, etc..

 

they make a 0W40 too ...

 

i wish i had more variety around here instead of having to order it.

 

Hard to believe considering where you live is supposedly the oil central of US.