Oil grade opinions/experiences?!

I have a 95? 940 HPT and need to do an engine flush and oil change.

My workshop manual suggest a wide variety of grades so I want to know what everyone else is using. Spec is standard at the moment but will get mild tune up to 200bhp within the next few months.

Also any recommendations on brands would be good too.

I use a Catrol GTX 20W50 on my 1984 2.3L B23F engine with approx. 200,000 miles on it.

I use Mobil-1 5/40 in them. They are always spotless inside and zero wear.

I use 10W40. Mostly Castrol Magnatec or Liqui Moly, whatever I can get.

Rotella T6 Synthetic 15w-40 (summer) or 5w-40 (winter) or Delo 400XSP 5w-40 Synthetic. What I run in my 740t or any red block.

Thanks for the responses guys.

My manual says to use anything between 10w30 and 15w50 so I think I?ll head down the middle with some 10w40, seems to be the cheapest to buy anyway.

My car has been sat for over 5 years and has over 180k miles on the clock. The oil is black and thin so I?ll be doing a full oil flush. As I?m a fan of regular oil and filter changes I?ll probably flush and change the oil every 2-3k miles 2-3 times to try and clean it as best I can.

OP we can help you better if you state your climate.

tintintin said:

OP we can help you better if you state your climate.

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What he said. Just picking one without considering the climate , I.e. the temperatures you will experience is counter productive.

The weight of the oil required depends mostly on the ambient temperatures, so your manual will guide you on that.

Some argue that an oil flush with some solvent like sea foam or others is asking for trouble, the flush may dislodge large particles of sludge and block oil passages.

The recommendation is to switch to synthetic which does a better job of removing sludge without causing these problems and change it more often the first 2-4 times.

I?d recommend Mobil 1 , but I?m sure some other synthetics would do just as well.

Perhaps run 15W-40. The 15W-40 will help to clean the engine. Rotella T 15W-40 is conventional heavy duty diesel engine oil. Rotella T5 15W-40 is semi-synthetic. Rotella T6 5W-40 is synthetic. Rotella T5 semi-synthetic is also available in 10W-30.

The Delo or Rotella 15w-40 is rather nice. It has been running in my 200K B230 for a few years now and it slowed multiple leaks until I had time to replace the seals.

It is also dirt cheap. The total cost of an oil change is about $20 including an OEM filter. Much better than the $50+ for my 2012 VW.

I'm in the UK around 20 miles north of London and we are entering our winter months now so temperatures are going to range between 10 and -10 degrees celsius over the next few months.

I think i will settle on some 15W-40. I will use a bottle of STP engine flush on my first change, as ive said its been sat for a very long time. It's leaking oil from what appears to be the rear crank seal and also from the oil filler cap, took the cap off and did the vacuum test and it blew the cap off which leads to a blocked PCV. I did a coolant flush on it a couple of weeks back and it took 7 flushes 1 with some rad flush before the water came out clear, the water jacket around the oil filter and the drain cock were completely blocked with sludge.

Hopefully once ive cleaned the PCV and with the use of the 15W-40 it will stem the leak and improve the driveability, its down on power at the moment as its only running around 6PSI of boost for a HPT.

I’ve settled on Rotella T5 10W30 for both 93 Classics. Oil pressure stays at 41-42 psi at 225-230 degrees. The valve train is spotless. I’ve also used Mobil 1 10W30 with excellent results too.

The_Geoffrey said:

I have a 95? 940 HPT and need to do an engine flush and oil change.

My workshop manual suggest a wide variety of grades so I want to know what everyone else is using. Spec is standard at the moment but will get mild tune up to 200bhp within the next few months.

Also any recommendations on brands would be good too.

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15w40 rotella. T4 usually. T5 or t6 if it?s on sale.