Mobil 1 is a group IV PAO based oil. It's about as true a synthetic as you're going to get.

I wouldn't classify many as true "race" oils due to their additive percentages. The good race oils don't make API certification for that very reason.

So why care? Well, when you've spent as much money on your engines as a lot of us have then it just makes sense that you should.

I've seen the proof in engine teardowns over the seasons. Longer valve spring life, less bearing wear and less wear particulate in engine oil samples. Blackstone Labs will do it for you if you're interested.

Either way, the right oil for one engine may not be the best for another. The amount of oil control the engine has is a big factor, but there are many. Have seen high powered race engines make power with particular weights of oil, only to see another similar build lose power with the same weight.

-Mindgame

 

now do these race oils have a disadvantage in daily driven tamer vehicles?

 

people interested in this issue, should consider
Delo-400 15w-40, from Chevron.

no group 1 {solvent refined} base oil
strong additives package
LOTS of zinc and moly

does NOT meet EPA requirements for SM
{a BIG plus, when the gov't does not like the stuff}

if you need 15w-40, consider this oil

 

This thread can open a can of worms....oil opinions are like a$$holes....

Personally I use Kendall GT-1 on my race motors, I use Mobil 1 Synthetic on all my streetcars, and chevron products for anything else (I am close friends with a chevron engineer and fully believe in their products) Diesel oils have higher thermal capabilities, and deal with the soot better. Mobil 1 has their "Truck/SUV" synthetic which is approved SL and meets diesel standards, it is also marketed under the Delvac 1 name which is a top choice by OTR truck drivers. Mobil 1 has now released a diesel specific oil too.

Delo 400 is a good oil, but if you use it in a HEUI diesel there needs to be an anti-foaming agent added, as this is one of the problems with that oil when run through a high pressure oil pump(500-4000psi).

 

Shell makes 15W 40...15w 40 is thicker so it more the likly would pro tect better...it can with stand heat better to....

 

What gives you the idea that 15-40 is better than 20-50?
Viscosity and weight do not determine how "good" and oil is.

Shell is cheap crap that I never use in my motors, almost down there with pennzoil.

 

Just wanted to jump back in to say two things:

1) Dirt track engines run looser clearences because they operate in a hostile environment and have to take into account that some sand WILL find it's way into the engine. Lots more than you will get in even a regular street driven daily driver.

2) Clearences and oil go hand in hand. The higher the viscosity the thinker the oil you need, and vice versa. The reason people have been looking to go with thinner oil and tighter clearences is because it seems to create less drag and therefore lower parasitic losses. The PROBLEM there is that while sufficiently loose clearences allow you to practically run crude oil right out of the ground; TIGHT clearences require better quality oil. Specifically synthetics, with their long chain polymers that wont shear under high pressure as easily as Dino oil will.

Personally, I like Amsoil and I like it for two basic reasons:
a) It's a Base IV oil.
b) They have a wide variety of products to meet my different needs.

I first began using them when I built a 1964 Sportster. That bike shares the oil among the engine, tranny and primary. That means that the clutch will eventually get oil on it and if you use too slippery an oil (withj friction modifiers), it'll destroy the clutch. Amsoil was the only company that had a high quality 20w-50 synthetic motorcycle oil WITHOUT the extra slippery additives.

 

I'm in the

Tight Clearances (.002-.0025 mains, .002 rods)
Std Volume w 55-60psi
Mobil 1 30weight 0W,5W or 10W depending on the cold startup pressure

Bret

 

Want to try that again - you lost me, even if I change the word to "thinner" or "thicker"? By "thinner" (or "thicker"), are you refering to film thickness, or are you using it as a synonym for viscosity?
Based on my knowledge, that's backwards. Long chain polymers are what is used as a viscosity index modifier in conventional motor oils, and its these long chain molecules that shear and cause a loss of viscosity characteristics in multi-viscosity oils. Synthetic oils achieve multi-viscosity characteristics by use of "designer" molecules, that do not rely as heavilly on the "swelling" with temperature that the long chain molecules use to achieve multi-viscosity characteristics.

 

LOL, yes... I would like to try that one again, this time without even using the word viscosity. Or Thinker. (Ironic, eh?)

Tighter tolerances need thinner oil.
Looser tolerances need thicker oil.



On the other issue, the way it was explained to me (and I'm pretty sure I'm relating this correctly), is that dino oil's molecules resemble elbow macaroni while synthetic oil's molecules resemble linguini.
As a result, the synthetic linguini does a better job of wrapping itself around stuff and holding on; especially when things get rough.
I think it has something to do with higher surface tension or something along those lines, but I'm a Network Nerd, not a Chemist.
But hey... if your Catalyst 8510 goes down, lemme know.

 

I agree with you about the Amsoil, they are top notch. I just don't use them that much.

 

Kendall is a popular choice and I use to use it too. When I really got into reading and learning about engine oils... having analysis performed after every weekend event, I switched to Royal Purple 11. I immediately saw lower iron, copper and other wear particulates in my engine oil samples. I also got maybe another 100 passes out of my valvesprings. Needless to say, I was sold. RP was also a sponsor of mine at that time but that doesn't influence my opinion of them at this date.

That said, a good race oil should be high in zinc and moly 1st and foremost. Zinc is the more effective EP additive but both are good antioxidents as well. RP has changed their formulations over the years just like everyone else. As far as race oils go I am a firm believer in RedLine and Torco because they are heavily designed for racing. I won't even get into weights other than to say what I've already said... it depends.

For instance... if I built a wet sump nitrous drag motor with low tension rings, my first choice in oil would not be the "lighter" viscosity stuff. The reasons should be obvious but yeah... the whole build has to be considered.

As for Amzoil, I'm glad there are guys who're happy with it. The big turn off for me with Am is in the way they market their product, MLM. In every oil forum out there you'll find some guy who won't admit that he's an Amsoil rep touting their stuff with all kinds of claims. All the analysis I've seen from their oils puts them about on par with Mobil 1 in my book. I'd save a few bucks a quart.

-Mindgame

 

For the record, I am NOT an Amsoil rep.

I just happen to like the stuff, so when the subject comes up I usually mention it.

For me the really nice part is changing the oil once a year. (My daily driver)
I still change the filter every 3000 miles though, on the theory that the oil might last longer but it's not getting dirty any slower.

 

That is exactly the MARKETTING Mindgame is talking about this onc3e a year oil changes crap, truth is the ONLY way you can confirm this is an acceptable practice in your car is to do oil analysis. Some people just eat up this over the top MARKETTING, more objective types see it as a HUGE turnoff though it is good oil.
It is hard to argue with the UOAs from the GC 0w-30 for at least stock bottomed LT1s and LS1s it seems to be about the best again this is based on lab data not opinion.

I have run Rotella T "synthetic"(group III so not like Amsoil or M1) 5w-40 in my LT1s and liked it well enough it is a Shell diesel oil. Definetely did some cleaning as I put it in and after a few hundred miles the engine got noisey a filter change quieted it right back down must have filled the filter with "dirt". It had had Amsoil for about 8 months prior with a few changes in that time as I put on a lot of miles engine was not anything anyone would consider dirty either. This oil is a mid priced oil and a decent but not spectacular performer as far as UOAs go kind of a "get what you pay for" sort of thing. Readily available at Walmart too and is dual rated for gas and diesel so no converter worries.

 

I don't remember the EXACT clearances for my motor but it was something like:

front mains= .003 +/- .0002 (could have been .0028 could have been .003)

rear main=.0035 +/- .0002 (could have been .0033 could have been .0035)

So I guess I'll try the diesel oil. Couldn't find any synthetic alternative at the local shops for a 15W40.