Which Oil for KU engine

[Ringmaster]

Hello Folks,

I've been using 10w/40 engine oil in my old C3 auto under the guise of Castrol Magnatec for a few years now simply because my local ASDA usually has a good deal on it.

My owners manual doesn't specify a grade of oil. It merely says to use a quality oil meeting VW standard VW501 etc., but it warns not to drive at high speed for long if using 5w/30 oil.

I've read that VW now prefers 5w/30 oil over 10w/40 because the latter has a higher risk of cam lobe warping in older engines, but various engine oil websites still recommend 5w/30 for my C3.

What do you think of the above? I'd like to stick with my usual 10w/40 Magnatec habit as I've had no issues, but the car has done 95k and oil has advanced since my owner's manual was printed in 1987. I drive about 800 miles a year.

[Isimmo]

Originally Posted by Ringmaster

Hello Folks,

I've been using 10w/40 engine oil in my old C3 auto under the guise of Castrol Magnatec for a few years now simply because my local ASDA usually has a good deal on it.

My owners manual doesn't specify a grade of oil. It merely says to use a quality oil meeting VW standard VW501 etc., but it warns not to drive at high speed for long if using 5w/30 oil.

I've read that VW now prefers 5w/30 oil over 10w/40 because the latter has a higher risk of cam lobe warping in older engines, but various engine oil websites still recommend 5w/30 for my C3.

What do you think of the above? I'd like to stick with my usual 10w/40 Magnatec habit as I've had no issues, but the car has done 95k and oil has advanced since my owner's manual was printed in 1987. I drive about 800 miles a year.

In my humble opinion 5w/30 is too thin for our era of engine. We have run 10w 40 for donkeys years in the 10 valve cars and a mixture of 10w40 or 10w60 in the 20 valve cars, again, without issue.

[tractor Dave]

Agree. 5/30 is too thin. If you want to put better oil in go for something like Fuch Titan fully synthetic but keep the grade.
What's more important is regular change, even with low use.

[mikes2]

I use 10W40 in my 20v. I've been doing that now for over 140k miles since I got it 16 years ago.

No plans to change to anything else.

10W30 really only started when they went to all alloy engines. Some of the newest ones are 0W20. Not suited to your Audi 100.

[BackintheFold]

I'm also using Magnatec 10/40 in my ur MB.

[oilman]

As others have said, stick with 10w-40 it will be ideal. If you want to go better just increase the quality.

Cheers,

Guy

[Ringmaster]

Thanks chaps......