Normally when I buy a new to me car I'll upgrade all the oils to synthetic, but I am concerned about the syn being too thin and causing any existing leaks to get worse.

Opinions?

Thanks

Justin

Shell Rotella oil. Plenty of zinc (which all synthetics lack).

Why is the high zinc content important? Where can I find this oil at?

Originally posted by JMyerz
Where can I find this oil at?

Walmart/Kmart/Autozone/Truckstop/etc

It's good stuff, #1 oil used in the over-the-road trucking industry.

Zinc is an anti-scuff agent that helps prevent wear due to metal-metal contact. I like the stuff for push-rod engines as the pressure on the cam, especially over the nose, is benerally greater than an over-head cammed engine.

You'll find zinc in most dino-based oils. Valvoline Race has the highest levels of zinc I've seen...and it's no surprise why RPi recommends it (Valvoline Race) for their hi-po TVR builds, especially as flat-cams are a reality with high-revving, high valve-spring pressure push-rod engines. Shell Rotella zinc content is not as high as Valvoline Race, but as Adam noted, it's a fleet oil and it has higher zinc content than most other brands. It's also relatively cheap at $6-7 per gallon (vs. $4 per quart for Mobil 1).

Synthetics (at least no pure synthetics) lack zinc. Zinc tends to accelerate the breakdown of catalytic converters and was phased out of the newer synthetics. Never had a problem passing smog with Rotella, so my cats are doing fine :D

Thanks for the lesson,

So if I do go with the Shell syn w/ zinc should I worry about the seals on the rover? I just don't want to cause any more leaks than I have to ;)

Justin

Rotella is not synthetic. It's a parrafin based oil as opposed to most which are asphalt based. The asphalt part of crude is cheaper and is what causes sludge buildup.

Originally posted by DieLucas!
Shell Rotella oil. Plenty of zinc (which all synthetics lack).

Wrong. Mobil 1 has plenty of zinc. More than Valvoline and Valvoline racing. Amsoil also has more zinc than valvoline, along with Castrol GTX. Mobil 1 has about 1400 PPM of zinc and about 1150 PPM of phosphorus (which is also an anti-wear add.- also called zinc dialkyl dithiophosphate [ZDDP]) for a total of 2500 PPM of anti-wear additives. Mobil 1 and other synthetics also carry more acid neutralizers, whic is for the long drain intervals associated w/ synthetics. Mobil 1 has 2196 PPM and Amsoil has 2946 PPM, which not suprising with their claim of 25k or one year drain intervals. I'm curious as to what Rotella has in terms of acid neutralizers? Im guessing it's less b/c of the high mileage vs. short time experienced by most OTR drivers.
If you really want high anti-wear additives in an oil check out Golden Spectro, Spectro 4, and BMW motorcycle oil. These oils are not subject to emmissions requirements (motorcycles don't have to be green) and have very high zinc and phosphorous levels
Golden Spectro: 1669 PPM Zinc, 1842 PPM Phosphorous, 3511 PPM total Anti-wear
Spectro 4: 1405 PPM Zinc, 1792 PPM Phosphorous, 3197 PPM total anti-wear
BMW Motorcycle oil: 1688 PPM Zinc, 1394 PPM Phosphorous, 3083 PPM Total Anti-wear
Now the EPA mandates less phosphorous levels in oil b/c it may damage late model catalytic converters. Back in the day, oil manufactures would load up oils with these anti-wear additives.

FYI: Valvoline has 1070 PPM of Zinc and 874 PPM of Phosphorous
Valvoline Racing has 1107 PPM of Zinc and 890 PPM of Phosphorous

...and for a comparison's sake
Wal-mart Super Tech: 499 PPM zinc, 798 PPM Phosphorous

And thus, he layeth the smacketh downeth.

You're absolutely correct :emb:

I misinterpreted the following missing data as 0%... :( my bad...

http://www.atis.net/oil_faq.html

BTW, some of the info UPOVR quoted can be found here:

http://www.amsoil.com/faqs/faq2.htm

And one last one:

http://www.ifsja.org/tech/figures/motoroil.shtml

note the high % of zinc content in Valvoline Race versus the Spectro oils. I do not know how these results were reported (as percentage by mass, volume, etc.); I would suspect photospectroscopy analysis to be more accurate, though...so, sorry about the misinformation. Garbage in, garbage out.

I got all that info from a recent article in BMWMOA Owner News. They sent off 14 samples of oils to an independent oil analysis firm by the name of National Tribology Services. "Tribology" meaning "the study of the design, friction, wear, and lubrication of interacting surfaces in relative motion- such as bearing and gears."
Good Article.

Here's something I don't get though. BMW N. America is big on not putting synthetics in their motorcycle engines until 12k-this is when they are finally "broken-in".
By looking at the analysis, standard non-synthetic BMW M/C oil has more anti-wear additives than their very own BMW SuperSynthetic. What gives? I'm running a superior oil until the machine "breaks-in" and the when all the parts are worn in and start to become loose they recommend an inferior blend?
Standard BMW M/C oil (cheaper) has more anti-wear additives than the Amsoil (really pricey-and recommended by dealer) that was put in my old bike at 14k!
Go Figure!:confused: