Is Oils oils??

I run my Cruiser on Penrite HPR deisel 15 and supply my own as I like it to stay on the same stuff because as you say some oils aint oils and dont always mix well .

Just my thoughts

I'm no expert but I'm pretty sure that the synthetic oils are very good. But whether they are that much better than normal oils to justify the price tag is debatable. When you've gotta change 10 litres of oil every 5000 km, for example, Mobil 1 gets very expensive very quickly. Too expensive for the average Joe IMHO.

As for changing brands/types, I don't know what type of vehicle you have but the advice I've always had with diesel engines is, pick a brand and type of oil that suits your vehicle/engine and stick with it. Chopping and changing between brands etc can cause problems. My advice is, go for a good, well known brand, find out which of their oils they recommend for your vehicle/engine and pick one which is readily available and not outrageously expensive.

Hope that helps.

matt

Some diesel mechanics believe semi synthetic is a better way to go because fully synthetic oil is too thin and can leak past seals and rings etc with some vehicles. When you get to the specialist top brands of oil such as Amsoil for example tests have shown the oil to be better in retaining viscosity in a demanding enviroment.

The debate over oil will continue but I believe better oils are worth the spend, so Oils ain't Oils..!

Signman

I run several old cars as well my daily use one, i was told a while ago that for cars that are intermittantly used not to use synthetics.

Although syntethics are a better oil they slide away from moving parts more, so in engines that are only started infrequently there is less oil on the moving parts when started. Hence more wear.

For these cars i buy a quality brand name and stick to it.

Alan

I use Castrol Enduron in my Merc diesel, Cruiser 4.5 Petrol and wife's Carolla.

Oils ain't oils, though they are a hell of a lot better than say 20 years ago. Enduron is a 5W40 full synthetic, able to take high temps (turbos) and engines that are working real hard in hot conditions (off roading, sand dunes etc).

In the Merc I change every 15,000 kays (it has a 9.? litre sump, and a 2.1 litre twin turbo), though the book says I can change every 30,000. Cruiser I change every 5,000 - it has a smaller sump and a large engine (book 10,000), and I cane it. Carolla every 10,000.

None of those engines use oil between changes.

I think a mineral oil wont cut the high temps found in modern engines though semi-synthetic can be good if you get a good brand (Penrite). However I note that in the Cruiser (and RR when I had it) when battling up steep 4WD roads (Vic high country for e.g.) that the engine maintainas a higher oil pressure with synthetics. It gets very hot under the bonnet when going hard and slow and a good oil helps heaps...

viz

oils aint oils...

valvoline

you know what i mean!