That's a good info to have, but when I check oil or change oil and see it has changed color so much, even 100% synthetic but comes out so black after 5k km, you wonder what happened in there. I don't like the look of it, I am sure the oil is fine but what causes the color to change is the reason I think most people change oil sooner than they should..... ! 

5 hours ago, JimShortz said:

That's cheap, but it is my understanding that there is a big difference between 100% Synthetic and Fully Synthetic - hence being able to get Fully Synthetic cheaper; a completely different base.

Yes but only a small difference. Not too important unless you are always revving on the ragged edge. I would prefer to pay more for 100 % Shell , but its not in my grade of 10/50. Unless some one knows of a Shell  10 or 15 or 20 - / - 50 or 60.

39 minutes ago, Agusts said:

That's a good info to have, but when I check oil or change oil and see it has changed color so much, even 100% synthetic but comes out so black after 5k km, you wonder what happened in there. I don't like the look of it, I am sure the oil is fine but what causes the color to change is the reason I think most people change oil sooner than they should..... ! 

This is very apparent in older vehicles. I had quite a few late 60s early 70s cars and you could change the oil and drive 10 miles and check the dipstick and the oil looked black.

 

Nowadays you can pull the dipstick on a new car and the oil is still a golden yellow color and the cars last oil change was 7500 miles ago which is why I keep it and use in other engines around my place.

 

Again with better engine fuel management, better materials, less carbon blowback into the engine, (Remember PCV's) Oil just doesn't get broken down and contaminated as quickly both Conventional or Synthetic. I wouldn't even think of changing a synthetic oil until 15,000 miles on any new car after the warranty period has expired. Let the dealer do what he must to comply then you own it.  btw this isn't about being cheap it's about what's practical and smart.

Yes, how much you rev the engine is also important. Although generally a 4 cylinder car engines (water cooled) and 4 liter of oil in it last longer and preserved better than a small 1 cylinder motorbike air-cooled engine with 800cc of oil - you can go a lot longer on cars with no oil change than bikes ....   (on geared bikes with slip clutch the oil is used there too, I heard that shortens the oil life too).

Edited May 25, 20188 yr by Agusts