Royal Purple vs Mobil 1

Dawkins

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It's oilchange time...syn...semi syn...basic...what do all you guys use?10w30...5w30...5w20...? Thanks guys
 
Dawkins said:
It's oilchange time...syn...semi syn...basic...what do all you guys use?10w30...5w30...5w20...? Thanks guys

5w20 conventional.
 
Mobil 1 in all my vehicles, but I have heard good things about Amsoil and Royal Purple. I would like to add "why" to the original question. As for me, I use a synthetic because it doesn't break down and I've got 20 good years in using Mobil 1.
 
i was told not to start using synthetic because it could start a leak
is that true?
 
Synthetic does not "start" a leak.

Synthetic will just find its way through existing leaks a lot easier. So, if you have a small leak, it may become a bigger leak.

Regardless, I have converted over 20 high mileage engines, 7 of which belonged to me, and never encountered such a problem.
 
Dominus said:
Synthetic will just find its way through existing leaks a lot easier. So, if you have a small leak, it may become a bigger leak.

I never understood this concept. If I use the same weight oil whether its conventional or synthetic, shouldn't it leak the same? Isn't synthetic just more of a lubricant so to speak? Isn't the thickness of 5w20 the same whether its conventional or synthetic?
 
basically, the molecules in synthetic oil are smaller than dino oil, so they can slip through seals easier.
 
67Continental said:
basically, the molecules in synthetic oil are smaller than dino oil, so they can slip through seals easier.


but the consistency is the same, I can understand extremely small leaks being found through synthetic over time (and with pressure) but for the most part it still doesn't make sense to me. The molecules combine to make the consistency, they don't separate just to fit through seals :p
 
I thought it was due to the detergents in the synth oil often cleaning gunk off seals that had been blocking leaks.
 
Jibit said:
but the consistency is the same, I can understand extremely small leaks being found through synthetic over time (and with pressure) but for the most part it still doesn't make sense to me. The molecules combine to make the consistency, they don't separate just to fit through seals :p


consistency isn't really a factor.....think of it this way. If you have a chain that is made of small links and a chain that is made of large links, the chain made of small links will fit through a smaller hole than that with larger links - even though the "consistency" of the chain - the fact that the molecules are still all linked together - is the same.

The detergent factor is another related issue.
 
Jibit said:
but the consistency is the same, I can understand extremely small leaks being found through synthetic over time (and with pressure) but for the most part it still doesn't make sense to me. The molecules combine to make the consistency, they don't separate just to fit through seals :p

You can have a liquid that has the consistency of peanut butter and leak through something that a liquid the consistency of alchohol will not.

Chemical properties will affect this type of behaviour more than anything.

One of the benefits of synthetic is that it gets into places that dino oils can't, which is why it typically lubricates better*. But this can also result in a small leak becoming larger.

The cleanliness of an engne has nothing to do with it leaking. You can run AutoRX or any quality engine cleaner through an engine and make it so it looks like a piece of chrome on the inside, have a leak not change at all, and then toss in synthetic and have it come out.

* the lubricating quality of an oil is dependent on its makeup, but given all else equal, the synthetic will be the better oil
 
quoted from web:

<<<<Another little-known downside is that switching to a synthetic oil on an old engine can result in oil leaks. Why? Because the detergents in the synthetic oils will "clean-up" the varnish and sludge left by conventional oils. If your engine seals are worn, the synthetic will break down the oil varnish that may be maintaining the seal. So it's not that the synthetic oil caused a leak, it just that it revealed worn seals by cleaning the varnish off of them. Many people have switched to synthetic on 100,000+ mile engines with no leaks, so it just depends on how often you changed your oil and the overall condition of your engine.>>>>>>>>>>...
 
Dominus said:
You can have a liquid that has the consistency of peanut butter and leak through something that a liquid the consistency of alchohol will not.

prove it! :D n can you guys tell i'm in the mood to argue today :p
 
The argument about detergents in synthetics doesn't fly. Convential motor oils have the detergents too. I've actually seen a real cheap no-name brand motor oil that said on the label "non-detergent", so other than that almost all of them have detergents. Here is an explanation on the Castrol site - there is no distinction between conventional and synthetics here:

http://tinyurl.com/howu2
 
why are some people using 5w20? Doesn't the mark VIII require 5w30?
 
synthetics are said to be more "slippery"

they will make existing leaks bigger or start new small leaks.


that being said.....i first put royal purple in my s10 when it had 130k miles. no leaks. no burning.


i have since switched all my cars to motorcraft dino or synth blend. its free (for me) and 1 hell of a good oil. i also change all my cars oil between 2500 and 3500 miles.


5w30 in the mark. there is a TSB stating they can be run with 5w20 so i may run it next change.
 
i run 10w40 on mine, and on all our cars.....nothing more, i live in the desert, 100-110+ all summer long.......why not put water instead of 5w20 :shifty: .......that stuff is way too thin to trust it in such a big engine, that just me though........oh yeah i use dino.......
 
Never heard of Amsoil is it anygood? Don't think they sell it in Canada i work for a Napa Autoparts...Never sold it before...We Sell alot of that syntec Castrol 5w30 and the Mobile 1...was just curious on what everyone was using and whats a tsb about 5w20 VR4?
 

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