in my 92, i use synthetic oil. i know that i cant go back to regular oil becuase it will damage the piston rings and start to burn oil. why is that? also, for my winter car, it has regular 5w30 oil for the winter, but its due for an oil change. can i use semi-synthetic oil for winnipegs -50 degree C plus winters and go back to regular oil for the summer?

 

You cant break in a motor with syn because the rings wont seat (supposively) but on a broken in motor, you can go back and forth, mix, do whatever and you will be fine.

 

I'm curious where that nosense about not switching back to regular oil came from. Heck I did just that last month or so. No problems. I had been running Royal Purple for a while but the motor developed quite a bit of blow by (I've heard of this with Royal Purple), and had started to leak a bit. So I went to Valvoline Max Life. Leaks can happen on an old motor that is seeing synthetic for the first time, so that wasn't a big surprise but no damage of any kind.

 

switching between syn and grade 3 or 4 (regular) oil is just fine, just like ist ok to switch companies. it probably started because of hype, syn is just better so ppl say not go to back. royal purple is hands down the best syn oil on the market today, dont let anybody tell you otherwise.

hey DLV555 whats this i hear about blow-by? whats the story on that?...does it create more pressure and leak out of seals?

 

just the talk of the town. i also herd that leaks can happen when you switch to synthetic for the first time, but my car has it already, jsut my winter mobile does not. what is semi synthetic made and what is the difference between regular and full syntheic

 

I'll take exception to that statement, but it's not worth an argument here.

As stated, that stuff about "can't go back" is not true. It is true that if you've been using synthetic and the engine is mechanically sound, there isn't a good reason to go back to petroleum based oil.

Synthetic blends are part synthetic base and part petroleum base. It's just a way to get some of the benefits of a synthetic at a lower price.

As mentioned, there are different grades or types of synthetic. The less expensive synthetics are typically highly refined petroleum - some judge a few years ago said it's okay to call them synthetic because they are highly refined, and that's practically the same as synthesizing them - in other words, he was clueless, and foisted this confusion on an unsuspecting public with his judicial fiat. AMSOIL, Mobil 1, Royal Purple, and Red Line are "true" synthetics (and I think the Lucas synthetics, but not completely sure about them). Almost everything else fits the "practically the same as" definition. The manufacturers aren't required to label their products with what they actually are.

 

ya thats right, mobil sued castrol because thier syn-tech oil was not a full synthetic but it acted just like it so the case was thrown out.

and perhaps 5-7kid i would like to have a civilized agruement on the best oil.

 

I wouldn't mind a discussion, but arguments are out of the question .

There have been many, many arguments about which is the "best" oil. Search and you'll see. It comes down to 2 things: 1) Very few actual facts are included in those arguments, and 2) different oils, including the "good" synthetics, aim for different goals. Meeting API and SAE specs is a piece of cake - they all do that, so no need to even discuss that. Beyond that, you're talking about wear protection vs. viscosity maintenance vs. change interval optimization vs. corrosion protection vs. anti-foaming, and each manufacturer shoots for different targets between those choices. So, I'll leave it at this: Pick AMSOIL, Mobil 1, Red Line, or Royal Purple, (and I'm starting my evaluation of Lucas synthetics - not their additives), which ever one meets the most of what you're looking for.

Personally, I'm running AMSOIL Series 3000 5W-30 heavy duty diesel oil (http://www.amsoil.com/storefront/hdd.aspx) in my flat-tappet engines, because it has the extra zinc and phosphorus needed for the sliding protection on the cam lobes which has been taken out of GF-4 oils, and higher total base number for corrosion protection as those vehicles also have more intermittent use; and AMSOIL 10W-30 (http://www.amsoil.com/storefront/atm.aspx) in my roller lifter engines, including the Camaro, because it doesn't have any viscosity index improver additive in it.

 

Gramps, I can't break it down for you (because I'm no engineer), but I've heard others complaining of excessive blow by when using the purp. I had a very bad case of it. LOTS of blows by. Oil fumes were over powering sometimes if you were just near the car. Especially when I had an valve cover breather instead of the breather pipe to the air cleaner. You could actually see it coming up from under the hood at times. I put the pipe back on because I couldn't stand it. I changed to MaxLife and it instantly went away. There might still be a little bit, but nothing like it was. It doesn't stink anymore and I could probably go back to the chrome breather and not worry about it.

 

ya im not gettin any smell...but i think i am getting a leak up at the balancer, but i dunno if switching oil will help that because its the only place its leaking.

diesel oil has too much detergents in it for my liking, more detergents means less room for Viscosity index improvers (VII's) and the base oil itself. i chose royal purple because it has the best resistance to viscosity breakdown. Viscosity breakdown will lead to engine trouble before dirty oil does.