Engine oil Q's

Nessism wrote: I'm unaware of any automotive/motorcycle oil on the market that doesn't have zinc and phosphorus in it.

You're right, I didn't mean to imply that zinc and phosphorous have been removed altogether, but that different additives like Boron and PTFE are instead being added instead of adding higher levels of ZDDP/ZDTP. Some suggest that for older engines you want as much zinc and phosphorous as possible, but that's not really necessary with modern additives.

gordone wrote: Looks like it’s common agreement around JASO-MA, but what about mineral? Semi Synthetic? Synthetic?

The main advantage of synthetic is that it lasts longer. They have fewer contaminants and don't break down as fast. They tend to keep their viscosity over time more and don't become as acidic. This alone is a pretty good reason to use it. This is also why modern vehicles have been able to increase their service intervals so much.

But a quality mineral oil will work just the same when new. Most synthetics have lots of additives (anti-wear addtives like we have mentioned, VI improvers, detergents, dispersants, oxidation inhibitors etc), and for the right engine these are fantastic. A good premium mineral oil can have the same, but it's less common - people are more inclined to spend more on a synthetic with all the additives than save a little for a mineral with all the additives.

But if you find a mineral oil that has everything you need and it's much cheaper than a synthetic, then there's no reason not to use it - just change it more regularly. Frequent changes also has the advantage of removing contaminants each time.

I personally use a Penrite semi-synthetic as it frequently comes up on sale, and I can't tell the difference between that and the full synthetic that I used to use.

Back in 1970, when I was looking to buy my first used car, a car with over 100,000 miles on it, was considered end of life.
Today it's more like 200,000. So is it because cars are better or oil is better?

ckahleer wrote: Back in 1970, when I was looking to buy my first used car, a car with over 100,000 miles on it, was considered end of life.
Today it's more like 200,000. So is it because cars are better or oil is better?

Both. Ed

Irish Yobbo wrote: The main advantage of synthetic is that it lasts longer. They have fewer contaminants and don't break down as fast. They tend to keep their viscosity over time more and don't become as acidic. This alone is a pretty good reason to use it. This is also why modern vehicles have been able to increase their service intervals so much.
.

Don't forget that synthetic doesn't thin out as much at super hot temps and the flash point is higher. I've read stories about guys with air cooled motorcycles stuck in traffic on a killer hot day where the oil got so hot it was starting to flash off and there was a ton of smoke coming out the tail pipes.

I'm a fan of synthetic oils although I typically don't use them in my bike due to the type of riding I do. Synthetic oils last a long time because they hold viscosity well and the oil manufacturers crank up the TBN Number with lots of acid buffers. One possible drawback is oil leaks though. The high level of detergent can clear sludge and such that's blocking oil passage to outside the engine. I've always struggled with counting this against synthetics but there are just too many reported cases of leakage to ignore. This is no guarantee that using synthetic will cause leaks mind you, but it won't help either.

ckahleer wrote: Back in 1970, when I was looking to buy my first used car, a car with over 100,000 miles on it, was considered end of life.
Today it's more like 200,000. So is it because cars are better or oil is better?

My parent's 1986 diesel hilux has almost 800,000km on the clock and my 1981 mercedes 280se has over 300,000. Neither blow smoke or have compression issues.

I think the main thing that kills high-mileage engines (apart from abuse) is simple economics. People are happy to spend hundreds each year on servicing their $15,000 modern car, but don't see the point in doing so for their $1000 25yo car. If you keep up the same level of servicing on just about any engine it will last. I got almost 400,000km out of a daewoo lanos just by changing the oil regularly. It would probably still be going if I changed the timing belt at the correct interval.

But back to the question - it's both. Engine oils are much better now, as are manufacturing standards. Newer cars have more parts to break, but it's very rarely the engine itself that's the problem. When a modern car breaks down it's usually a crank-angle sensor, or management, or injection - all the stuff around the engine. With a few exceptions, almost any engine from a reputable manufacturer will outlast the rest of the car provided it's maintained and not abused.

If you have a little time to [strike]waste[/strike] read through this guys blog... 540ratblog.wordpress.com/2013/06/20/moto...l-wear-test-ranking/

He's opinionated as all get out, and no doubt one of those guys that throws gasoline on oil debates, but I think he makes a lot of good points. I bought some car oil based on his recommendations. Good fun.

Interesting indeed, though I had to wade through a lot of repetitious preaching to get to the heart of the matter.