This forum regularly encouters queries regarding what oil to use. Personally I think people are sometimes misguided.

 

I have never heard about an engine falure on a Z that that was due to "poor" or incorrect oil.

 

Personally I reckon all branded oils are quality oils and are up to the job - i'm not talking about halfords multigrade. The difference in wear rate and protection between quality oils is so minimal that if you were to split the engine it would be very difficult to notice the difference and is not appropriate to an average life span of a car. It would probably takes 100,000's of miles before it became important.

 

As for viscosity, After speaking to Mobil, they recommended a lower viscosity for newer engines and a higher viscosity for older engines. Makes sense to me.

 

I read a report from a specialist (does ne1 remember the link?) who stated that car owners were in fact concentrating on the wrong area. The pistons wear considerably more than the other components particularly on warm-up. He advised that you should NOT let your car idle too long on warm-up! This promotes an acid build-up which erodes the pistons. A car should be driven causiously on warm up rather than left to idle as driving the car helps remove the acid build-up produced when the engine is "cold". For turbo cars, drive cautiously ensuring that you don't exceed 0 pressure until the car has reached operating temperature.

 

Obviously you need to use a quality oil especially for modified and highly stressed engines and fully synthetic is always recommend, however I would'nt go too much into comparing the top brands - just stick to good brands and get the correct viscosity for the age and condition of the engine. Also change regularly.

 

I have heard a Z running with Mobile 0/40 and it sounded awful (top end noises) - it was changed to 15/50 and it sounded a lot better. Why? because it was high mileage and had seen better days.

 

I have heard another Z with 0/40 that sounded great. Why? beacuse it was low miliage and looked after.

 

Hope this helps

 

Andy

 

Oops, forgot to mention the get out clause! This is only my view based on my obversations. No court cases please. I don't yet have a doctorate in mechanical enginnering of the combustion engine variety LOL.

In principle I agree, which is why I gave up on Mobil-1 and now use a trade oil (Multiline, fully synth 10w/50)

 

The best oil for a Zed is clean oil - change both the oil and filter regularly. And if you want extra insurance use one of those magnetic things to capture the steel grindings.