Full synthetic engine oil comparison: Mobil 1 vs Castrol
 

Im considering switching from Mobil 1 to the Castrol full synthetic Ive been seeing lately. Does anyone have any historical/peformance data on the Castrol Full synthetic as comparted to Mobil 1?

Re: Full synthetic engine oil comparison: Mobil 1 vs Castrol (MELVIN)
 

Mobil 1 tried to sue Castrol claiming that Syntec does not use a true synthetic basestock. I think there may be some merit to Mobil 1's case. Even prior to hearing this I was a diehard Castrol dino oil user. On my new vehicle however, I use Mobil 1 or Royal Purple.

I think a lot of the "best oil" debates are just hype but it makes for some interesting reading....sometimes.

From http://www.micapeak.com/bike/ST1300/Oils1.html

"In the late 1990s, Castrol started selling an oil made from Group III base oil and called it SynTec Full Synthetic. Mobil sued Castrol, asserting that this oil was not synthetic, but simply a highly refined petroleum oil, and therefore it was false advertising to call it synthetic. In 1999, Mobil lost their lawsuit. It was decided that the word "synthetic" was a marketing term and referred to properties, not to production methods or ingredients. Castrol continues to make SynTec out of Group III base oils, that is highly purified oil with most all of the cockroach bits removed.

Shortly after Mobil lost their lawsuit, most oil companies started reformulating their synthetic oils to use Group III base stocks instead of PAOs or diester stocks as their primary component. Most of the "synthetic oil" you can buy today is actually mostly made of this highly-distilled and purified dino-juice called Group III oil. Group III base oils cost about half as much as the synthetics. By using a blend of mostly Group III oils and a smaller amount of "true" synthetics, the oil companies can produce a product that has nearly the same properties as the "true" synthetics, and nearly the same cost as the Group III oil. In fact, Mobil-1 is now primarily made from Group III unconventional base oils, exactly the stuff Mobil was claiming was not really synthetic. The much more expensive traditional synthetics are now available in their pure forms only in more expensive and harder to obtain oils."




[Modified by Neo Fender, 8:42 AM 8/4/2003]

Re: Full synthetic engine oil comparison: Mobil 1 vs Castrol (Neo Fender)
 

Neo,

Thanks for the info, really interesting stuff. To me anyway, but I'm a systems geek(read: engineer) so this stuff is a good read for me.

Re: Full synthetic engine oil comparison: Mobil 1 vs Castrol (tersian)
 

That's just depressing. What kind of brutalizing of the English language is involved in some judge deciding that "synthetic" actually means "dino oil that's almost as good as real synthetic."

So are there any easily available commercial products that are actually honest-to-God 100% man-made synthetic?

JB

Re: Full synthetic engine oil comparison: Mobil 1 vs Castrol (Neo Fender)
 

Quote:
"In fact, Mobil-1 is now primarily made from Group III unconventional base oils, exactly the stuff Mobil was claiming was not really synthetic."

That statement is absolutley not true . The Mobil Supersyn is comprised of various viscosity PAO's with a fantastic additive package. It is the best Mobil oil ever offered for a Passenger car and is more VI stable compared to the Syntec analysis's I have seen .

The only Mobil oil that uses group III basestocks is called System-S and is a 5/40wt offered in Europe only. The new 5/20 they have might be a group III basestock but you will not see Mobil call it a Synthetic anytime soon.

Group III fake synthetics are not all that bad , in the new 5/40's PCMO's anyway . These generally use a small amount of PAO in them along with a tweeked additive package that merits a look at, seeing these oils are generally 2.90 - 3.50 per quart and meet the VW 505 , Mercedes Benz 229.3 and BMW service fill along with these specs comes a High Temp/High Shear of over 4.2. For a 4-6k drain interval I ,IMO , would put the following oils up against any of the mail order oils in terms of protection and cost vs performance if the motor is of the type that could actually use a low to mid VI 40wt.

Kendall GT-1 5/40
76 Full Syn 5/40
Castrol 5/40 - not to be confused with Syntec
Chevron 5/40
Valvoline 5/40

For warmer climates or the hotter cammed OHV V-8's the new Diesel 5/40's with the API service SL " gasoline engine " just might be the ticket for some.

These include the

Rotella T 5/40 with it's Slack Wax Base Oil
Valvoline Premium Blue Extreme 5/40 - group II,PAO
Petro Canada 5/40 Group III
Citgo Syndurance ----it's a PAO,group III,II blend


There is more but that's what came to immediate mind as good to great new contenders on the block.

Re: Full synthetic engine oil comparison: Mobil 1 vs Castrol (mountainmotor)
 

Mobil 1 for me. :yesnod:

Re: Full synthetic engine oil comparison: Mobil 1 vs Castrol (MELVIN)
 

According to the Amsoil website, their synthetic is made from 100% PAO base stock and additives, no Dino oil in the base stock.

Re: Full synthetic engine oil comparison: Mobil 1 vs Castrol (Smokehouse69)
 

Yeah but go back to their site and see the 7500 series oils they tout as " Synthetic " . That oil is only a group III basestock .

They advertise true PAO's and then do an about face...they can't have it both ways :p: Or can they ? Guess so if the consumer is not educated on their way of advertising.

Marketing Hype gives some oils bad names

:sleep:

Re: Full synthetic engine oil comparison: Mobil 1 vs Castrol (mountainmotor)
 

Curtis just tried to call you.

Re: Full synthetic engine oil comparison: Mobil 1 vs Castrol (mountainmotor)
 

I've had good luck with Amsoil.....over 100k on both my daily drivers, with no engine issues, and I only change the oil once a year on both since new. '93 Chevy P/U, and '98 Ford Expedition

Re: Full synthetic engine oil comparison: Mobil 1 vs Castrol (MELVIN)
 

This info is based on rider mower experince; broke it in with Quaker State dino and switched to Mobil 1 and it ran great. Keep in mine I mow and use it for snow removal too.

Last summer switched to Castrol full synthetic and in the summer heat my engine started knocking so switched back to Mobil 1 and the problem went away.

I will never use Castrol full synthetic in anything again, the mower is much different than a car for one it's air cooled.

Re: Full synthetic engine oil comparison: Mobil 1 vs Castrol (WydGlydJim)
 

Sure, some people swear by $.99 walmart oil, never any problems. I dont, but my point is as I am sure others, if you are paying high dollar for Synthetic oil, you want what you are paying for....

Re: Full synthetic engine oil comparison: Mobil 1 vs Castrol (LAvetteman)
 

I get Shell Ultra Helix competition 10W60 (Ferrari Challenge) for free so why run anything else :D

Re: Full synthetic engine oil comparison: Mobil 1 vs Castrol (LAvetteman)
 

Not to appear argumentative, :D But......The Amsoil I use is 100% synthetic, and Amsoil was "first in synthetics", and around long before any of this litigation over blends, which is really what we are talking about. I don't think any of these other oils claim to be 100% synthetic, and if they do, it is false advertising. As far as being high priced, I just don't look at it that way. If I use an oil that is three times as expensive. but offers 5 times the life over conventional oils, where is the added cost. There is none. As far as getting what I pay for, I do. I get a quality motor oil, that is comparable in cost to other oils, and the advantage of much greater service intervals which saves me time, ( which is really the most important to me ) and it is better for the planet. Any way you look at it with an open mind, Amsoil is the smart choice. Damn, they should pay me for this advertising!
:cheers:
http://temp.corvetteforum.net/c5/wyd...//dsc00166.jpg

Re: Full synthetic engine oil comparison: Mobil 1 vs Castrol (MELVIN)
 

Here's my experience. The ONLY oil related problem I have ever had was with a 92 Corvette that had ALWAYS been serviced from day one at a chevy dealer with Mobil I before I got it from the 1st owner. I continued using Mobil I . A 90 k a lifter gaulled.. Stuck up causing a very difficult to find miss. But the engine was clean... Tide would have done that.. :lol: :lol: I have 184K on my 3.1 Lumina APV.... Valvoline... NEVER touched the inside on the engine. Doesn't smoke,or use oil and still runs perfect. No synthetics in my cars....

Re: Full synthetic engine oil comparison: Mobil 1 vs Castrol (bluevetteman)
 

Motorcyclist Magazine had a good oil comparison article a month or 2 ago. It mentioned a lot of the points in this thread and convinced me to switch from Castrol to Mobil 1. The article was obviously bike-focused but most of it applied to oil in general.

Re: Full synthetic engine oil comparison: Mobil 1 vs Castrol (wingnut)
 

I just switched to Mobil 1 after reading this article. Hey maybe its all BS, but perception is everything.

Re: Full synthetic engine oil comparison: Mobil 1 vs Castrol (MELVIN)
 

Use a decent SG or better rated "dino" oil and change it every 3000 miles. You'll do just as well as any synthetics and pay 1/4 of the cost. If you want to run synthetics, you should still change your oil every 3000. So if you want to pour that extra $3/qt down the drain all the power to ya if it makes ya feel better. The biggest factor that I've seen with respect to wear and carbon accumulation in the 100K+ fleet motors that I've looked at (and we run 'em all over the country) is the regularity of the oil changes--synthetic oil or not.

When Mobil 1 first came out, they touted that you could extend your oil changes out to 25,000 miles. They back peddled on that statement really fast when customers started taking them literally.

Re: Full synthetic engine oil comparison: Mobil 1 vs Castrol (LemansBlue68)
 

Actually I read a report many moons ago about A german car company that did a test using two different oils, Dino and Synthetic. THey put something like 100,000KM's on the cars, doing oil changes every 5000 Km's. The car with Dino oil had the engine wear of car that had a 100,000KM's, no surprise there. The car with Synthetic had athe same engine wear as a car with about 10,000 KM's of wear. So, if I could find the article I'd post it, but I can't but I did read it. So, for me Synthetic is the only way to go.

Re: Full synthetic engine oil comparison: Mobil 1 vs Castrol (LemansBlue68)
 

What do you base this opinion on?

Here is a guy that is running M1 and sending a sample in for analysis every 1k miles: http://neptune.spacebears.com/cars/s.../oil-life.html
You will notice that the rate of the wear items (mainly Iron and Lead) did not really increase untill the oil was getting 10k+ miles on it. In fact the 6000 mil to 9000 mile interval had just about the exact same wear as the 0 - 3000 mile interval.