Thread: What Oil do you use for the P38!!

Hi There,
I use Royal Purple 10w-40, fully synthetic in the engine, change the oil every 10,000 klms and the filter every 5000 klms. No problems so far and the engine is clean enough to eat your dinner off, not to keen on the flavour though.

I have this regime based on oil analysis, tried to add a bit of science to the decision. As far as I'm concerned cleanliness is next to godliness, a clean oil is better for your engine no matter what brand of oil you use.

Did some load testing on a film strength testing machine and the Royal Purple came out head and feet against any competitor, some of which are mentioned above. The closest competitor was the Mobil 1 fully synthetic.

That's my 5 cents worth.

Originally Posted by Nomad9

Hi There,
I use Royal Purple 10w-40, fully synthetic in the engine, change the oil every 10,000 klms and the filter every 5000 klms. No problems so far and the engine is clean enough to eat your dinner off, not to keen on the flavour though.

I have this regime based on oil analysis, tried to add a bit of science to the decision. As far as I'm concerned cleanliness is next to godliness, a clean oil is better for your engine no matter what brand of oil you use.

Did some load testing on a film strength testing machine and the Royal Purple came out head and feet against any competitor, some of which are mentioned above. The closest competitor was the Mobil 1 fully synthetic.

That's my 5 cents worth.

Falex test ?

Not really indicative of an oils suitability on an engine oil.
One of the best engine oils in terms of Falex numbers I saw twenty years ago had some of the worst wear results in use!

And probably a waste changing the filter every 5,000km, full flow filters aren't really filters, most, eg. Z9's only filter in the 27-30 micron (nominal) range.
Real filtration occurs around 1 micron or so.

Looking back at my post in 2012, I stand by my choice of Valvoline SynPower 5w40. I changed to Penrite 5w40 two changes ago and it became tappety on cold starts, so I went back to my Valvoline and that fixed the issue.

I run britpart oil filters, have done so for nearly 4yrs.

Cheers
Keithy

Originally Posted by kapowww

Just reviving this thread as I want to do an oil/filter change and there are too many opinions! Need help with what to use in my HSE with 230xxxkm. Synthetic or not? Viscosity?

Also with the oil filter, Z9, Z89a or genuine Land Rover?

I know I'm probably opening a can of worms again but some may have renewed perspectives?

Yeah just be a bit carefull when choosing synthetic over mineral based oils.

If you or the previous owner been using mineral based oils throughout the life of the vehicle, it's not a good idea to change to full synthetic now without an engine overhaul, cause the change of oil base will react with all your oil seals in the engine to producing more oil leaks ( like as if the P38 doesn't already leak enough).

To be on the safe side I'd use a good premium brand mineral oil, or you can maybe just go up to a semi- synthetic oil and see how you go.

Another issue is that engines that have run mineral oils over time will have oil baked onto certain parts. The sudden change to synthetic oil due to it's high detergent ingredient will remove that as part of the cleaning process and block all the oil galleys and pipes causing oil surges around the engine.

With oils, it's a case of you stick with one base or another throughout the life of the motor. Usually what is started of with from the factory.

Originally Posted by rick130

Falex test ?
And probably a waste changing the filter every 5,000km, full flow filters aren't really filters, most, eg. Z9's only filter in the 27-30 micron (nominal) range.
Real filtration occurs around 1 micron or so.

So, what do you suggest as far as filters go Rick?

TIA
Steve

Hi Rick130,
Happy thoughts.........this may not come as a great surprise but I use the RP oil filter as well not down to 1 micron however significantly better than the 27 to 30 micron you mention. Hence the reason I change it more often realising it is likely to get blocked / contaminated quicker.
As I said it was only 5 cents worth, what I do, I just offered an opinion which works for me which is what I thought all this was about. I didn't expect a mass migration over to Royal Purple.
Typically on turbo machinery we run a 10 micron filter only on gas seal systems do we go sub 5 micron, of course what you say is right however if filtered at 1 micron you would need a filter the size of a bath tub to get a realistic time period between changes.

Just another 5 cents worth............

Originally Posted by Nomad9

Hi Rick130,
Happy thoughts.........this may not come as a great surprise but I use the RP oil filter as well not down to 1 micron however significantly better than the 27 to 30 micron you mention. Hence the reason I change it more often realising it is likely to get blocked / contaminated quicker.
As I said it was only 5 cents worth, what I do, I just offered an opinion which works for me which is what I thought all this was about. I didn't expect a mass migration over to Royal Purple.
Typically on turbo machinery we run a 10 micron filter only on gas seal systems do we go sub 5 micron, of course what you say is right however if filtered at 1 micron you would need a filter the size of a bath tub to get a realistic time period between changes.

Just another 5 cents worth............

The TD5 centrifuge filters well down to low levels, but it is a by-pass filter.

The best full flows use Donaldson or Fleetguard synthetic medias and IIRC are around 6-7 micron nominal.

Originally Posted by redandy3575

Yeah just be a bit carefull when choosing synthetic over mineral based oils.

If you or the previous owner been using mineral based oils throughout the life of the vehicle, it's not a good idea to change to full synthetic now without an engine overhaul, cause the change of oil base will react with all your oil seals in the engine to producing more oil leaks ( like as if the P38 doesn't already leak enough).

To be on the safe side I'd use a good premium brand mineral oil, or you can maybe just go up to a semi- synthetic oil and see how you go.

Another issue is that engines that have run mineral oils over time will have oil baked onto certain parts. The sudden change to synthetic oil due to it's high detergent ingredient will remove that as part of the cleaning process and block all the oil galleys and pipes causing oil surges around the engine.

With oils, it's a case of you stick with one base or another throughout the life of the motor. Usually what is started of with from the factory.

Strongly disagree.

All oils are formulated to be compatible with modern seals and are pretty neutral in terms of seal swell.
Most syns don't inherently have more detergency due to their base oils except predominantly ester based fluids, eg. Redline, Motul and Neo, and any decent mineral HDEO will have far more detergency than any petrol biased syn oil.