which oil

[911mark911]

hi all, I have a 2001 chevy express 8.1L with 110k miles
and want to do an oil and filter change so just wanted advice on
5w-30 or 10w-40 full or semi synthetic also is it worth using slick 50
thanks for any advice

[balls-out]

911mark911 said:

hi all, I have a 2001 chevy express 8.1L with 110k miles
and want to do an oil and filter change so just wanted advice on
5w-30 or 10w-40 full or semi synthetic also is it worth using slick 50
thanks for any advice

I am no expert, although I have a little more background than some - I studied lubrication as part of my degree and have read widely on the intranet - both accurate and rubbish out there.

IMHO:
Slick 50 (and other additives) is to be avoided totally. Based largely on PTFE properties - the makers of PTFE do not recommend it for engines and neither does any car manufacturer. There are some good scientic justifictions to avoid it on the web, that convince me. Snake OIL and a con.

Quality Synthetic oil will be superior to cheaper semi and Dino. in extreme condition of heat or cold synthetic will give more consistent protection.

Use the spec recommended by the people who built the engine ie read the handbook. _IF_ there is a choice err on the side of the thicker ratings. Whilst its tempting to argue that a worn engine might benefit from a thicker oil, my gut says on balance not. I don't think 110k miles counts as a knackered engine though.

As I said I am not an expert, and this is just what I do for my cars. Its a seriously complex area if you relly get into it. I usually use mobil1, and can't decide is I've just fallen for the hype or not - its expensive, but in the 20 years I've used it, I've never noticed ANY engine wear that the properties of the oil might affect (ie bearing, piston slap etc), which makes me thing it might be money well spent. Loads of other stuff has broken though

Also regular oil changes are important. Less the case for you, but many modern cars come with excessively infrequent oil changes to reduce the running costs for fleet buyers. IF you want to keep it regular oil changes are recommended.

Edited by balls-out on Thursday 6th February 13:14

[911mark911]

hi thanks for that much appreciated