Mobil 1 v Motul engine oils.

[lwells]

May as well link this thread: http://www.skylinesaustralia.com/forums/sh...ead.php?t=66729 -- why not to use Penrite

LW.

[JimX]

Ok here's something that I have only discovered recently. This is to do with my motorcycle, but since oil is meant to remain as consistent as possible between changes I think it can apply to a certain extent to cars. The main difference between my bike and car is the operating temps, as the bike has no turbo.

In the past I have been changing the oil in my bike every 3000km (factory specifies 6000km). However at between 1000-2500km, I noticed the (wet) clutch grabbing significantly more than when the oil was fresh. To me that means the oil friction properties have changed, because the oil is now allowing the clutch to slip differently than when the oil is fresh. Even though this means the clutch is slipping more, I fail to see how the oil could be getting BETTER over time. Oils break down in engines, they don't get better.

This happened across the board no matter what oil I was using, and I noticed that the "cheaper" oils would do it earlier than the more expensive ones. The oils I used in the bike in order of worst to best are:

Castrol Formula R 5W-30

Castrol Formula R 10W-60

Shell synthetic 10W-40 (designed for motorcycles)

Motul semi-synth 15W-50 (designed for motorcycles)

Mobil 1 5W-50

Fuchs synthetic 5W-50

Motul semi-synth Turbolite 10W-40

The weirdest thing here is that the oils designed for motorcycles are only average at best. The reason I tried car oils is because I read a review on the net saying that motorcycle oils aren't necessarily better for bikes. The most surprising thing is the Turbolite oil I've got listed at the end there, which I used for the first time in my most recent oil change. I accidentally missed my usual 3000km oil change because I was waiting for the clutch to slip to know when I should start paying attention to the odometer (I have to push a button to cycle it between the trip meter). But it's still working exactly the same as when the oil was new, after 3500km. Because of that I'm going to see if it can do the full 6000km without having to change the oil.

I don't get it. A cheap semi-synth is better than a full synth costing 50% more? I also don't understand why Motul have a car oil that's better in a bike than their bike oil. Just marketing at work I guess. I still use the more expensive 5W-50 8100 full synth Motul in the Skyline, but mostly because the turbo runs a lot hotter and I think a semi-synth will break down too quickly because of that.

Anyway I'm sold on Motul. I don't see any need to buy other brands again, unless Motul changes their formula for the worse.

[Ronin 09]

So do the Castrol oils not have the detergents that the others such as Motul or Mobil 1 have?

[JXL]

I haven't seen it mentioned but can i bring Castrol Magnatec into the equation? The promoted stuff about it reducing all that engine wear at start up etc. its viscus rating aswell is 10W so pretty low.

I see many of you are mentioned how the oils suck up all the dirt and carbon which causes it to go black so basically reducing the engine wear which magnatec says it does.

anyone got any results?

i have used Mobil 1 before and didn't really notice the difference between taht and castrol.