General consensus on best oil grade ?

[graeme4130]

Hi all
Is there a general consensus on the best oil grade to use
The recommended is mobil 1 5w/50 if I remember rightly, but I'm not convinced this is totally suitable for normal driving.
Mine's a 95 4.0hc with 47k miles
I'd he interested to hear what everyone else is running in there's ?
Cheers in advance for your advice
Graeme

[Dr Mike Oxgreen]

You won't find a consensus I'm afraid!

IMHO, people agonise too much about the grade of oil, and the synth/semi debate. For good engine longevity, you need an oil with a decent zinc (ZDDP) content, and you need to limit your revs until the engine's warm.

[graeme4130]

Cheers
In the short term though, the previous owner had filled it with fully synthetic mobile1 0w/50 or 0w/40 (he wasn't 100% sure which)
it's going in for a 12k service in three weeks anyway, so will be fully flushed and refilled, but my question is that in the meantime if I top it up with another grade of fully synthetic mobile 1 (ie I use 40 or 50 or even 5w/50) is that going to do any damage ( ie potentially mixing fully synth 0/40 with fully synth 10/50 for example)?

Sorry if this is s numpty question, but a google search returned all sorts of contradicting answers

Thanks

Graeme

Edited by graeme4130 on Monday 11th July 13:45

[hurststeve]

Won't do any damage.

[ralphy12345]

I took my newly-acquired Chim to Dulford Automotive for its service and Mobil 1 15/50 was their recommendation and what they used on the service.

After that I discovered a stack of receipts from the previous owner and it would appear that the same oil was used throughout the car's life.

I'm also of the opinion that regular oil changes and no hard acceleration until warm will have more effect overall on the engine than a small change in viscosity.

R

[Andy JB]

I have used different grades when i first had my 500, and IMO i think 10w/50 is the best grade all round.

Thinner oil does sound more tappety and consumes more, plus is very thin for an older design. Conversely, 15 or 20w oils i think were too thick at cold start up & you can hear the poorer circulation on start up on a cold morning.

Consequently i have gone for 10/50 fully synthetic which seems a sensible approcah all things considered, plus recom by Opie Oils. It doesn't consume much between services and flows well on start up and 50 makes it stable at 100degrees.

I have decided to leave it for longer between changes using synthetic as its designed by definition to last longer and 6 months use after a couple of thousand miles is a bit of overkill changing it annually ie after 6 monhts use.