Printable Version of Topic

Posted by: jfort Jun 3 2004, 09:30 AM

I can believe this hasn't been discussed ad nauseum, but I did a search and couldn't find anything. Time to change oil. Any suggestions as to which oil to use?

Posted by: ArtechnikA Jun 3 2004, 10:02 AM

interesting...
i did a search on "Valvoline OR Mobil-1" and got 2 pages of threads ...

Posted by: newdeal2 Jun 3 2004, 10:11 AM

I have discussed this on Yahoo and the general anwser is if you don't run synthetic then go with Castrol GTX 20 w 50.

If synthetic go with Mobil-1 15 w 50 but it will "find leaks" so beware.

Posted by: MattR Jun 3 2004, 10:57 AM

Jake suggests Kendall in his video, but I need to find a store that has it so I can buy a case or two. All I can find are the big ones (penzoil, mobil, valvoline, etc.) at the locat chain auto store.

Posted by: ArtechnikA Jun 3 2004, 11:05 AM

Harley-Davidson used to specify Kendall, a HD dealer or bigger bike shop should carry it in quantity. my preference is Mobil-1 15W-50 -- that 0W stuff is great in modern water-cooled engines designed with appropriate bearing and hydraulic lifter clearances designed for it, but it's much too thin for an air cooled engine...

Jake's said here in the past that he likes Valvoline Full Synthetic and Royal Purple synthetic.

i wouldn't use a synthetic as a break-in oil, and when i changed the 911 to Mobil-1 15-50 i did the first couple fo changes pretty close together, with new filters - on the theory that any new sludge they manage to dislodge should be got out quickly.

Pennzoil/Castrol don't actually make anything - they're just repackagers. it's your engine, do what you want - but i bet you won't find many builders specifying them for their builds...

Posted by: ChrisReale Jun 3 2004, 01:44 PM

I broke my 914 engine in with Kendall 20-50 and switched to Mobil 1 15-50. My 1986 Subaru has 234,00 miles on it, and I have used castrol 10-30 at all times and the compression is still good and it dont burn oil at an unreasonable rate so...

Any modern oil will prolly be ok, just make sure it gets changed at the right times and the right ammount is in the engine at all times.

Posted by: Carrera916 Jun 3 2004, 01:53 PM

For long time, I always use Castrol stuff....I guess I cant get away from these bean oil..Castrol R....gotta sniff these stuff for yourself someday...especially when stand behind the real 4 cammers....

I tend to use the petroleum based oil like Castrol till the engine breaks in then switch over to Amsoil synthetics...

Old engines, yes, the synthetics will find it's way out but if you have replaced all seals which is pretty easy to do with TIV, then switch to synthetics, I pretty much never ran into leaking problems...that's if the sealing job are done right....

check the Amsoil website....real good stuff...been there first before any of these mega big oil corps and they're having hard time matching the Amsoil....

j

Posted by: Tom Perso Jun 3 2004, 02:04 PM

I use Shell Rotella T, 15W-40. It's Diesel oil so it's high in zinc for anti-scuffing.

Comes in 4 quart containers and it's easy to buy and do an oil change.

As long as you keep the level up, change it often, and don't use Penzoil.

Later,
Tom

Posted by: Jake Raby Jun 3 2004, 08:32 PM

No luck with Mobil 1 in a TIV for me...
Royal Purple and Valvoline synthetics work well..
I stick with Kendall for conventional oil.

Posted by: ChrisReale Jun 3 2004, 08:43 PM

Jake, I have seen you say this many times. What concrete "evidence" do you have that shows other synths out-perform Mobil 1 in a Type 4? I am very curious. I know you practically have a dyno attached to your hip, what has it told you?

Posted by: Jake Raby Jun 3 2004, 09:13 PM

3 days of dyno work on the same engine, same load and same temps....

The Mobil 1 ran 30 degres HOTTER than the others. I never saw any HP gains between the 6 oils I tested.

Some made the engine seem to rev faster, thats about it...

I also tried the Mobil 1 in our FP car directly against a conventional oil and the conventional oil ran cooler! Same day, two differet sessions!

Posted by: reverie Jun 3 2004, 09:33 PM

Thank you for posting that, Jake.

I have been told that synthetics don't absorb heat as well as conventional oils, and your data seems to verify that.. but your other data leaves me confused. In a typical air-cooled engine (where oil plays a role in engine cooling), does it make sense to use a good conventional oil for better cooling?

Posted by: Jake Raby Jun 3 2004, 09:43 PM

A few synthetics work well in these engines, but not all cases are the same..

What you were told was probably written when the only synthetic on the market was Amsoil- it sucks ass!

I have ran Royal Purple in my 912E for 54,000 miles (thats 21 months of driving) and the oil thats in it now was last changed 8,000 miles ago... I change it when I see a puff of oil smoke between gear shifts- till then I just swap filters once a month or so..

My Bus has had the same oil in it for two years- its Valvoline Synthetic.

Both these yield oil temps 2-30 degrees less than any conventional I have tried in these engines...

Yes, I have been purposely abusing my cars for years- I try to break them. Risk and development baby!

Posted by: MarkV Jun 3 2004, 10:24 PM

May 2004 Exellence Magazine had an article on "Motor Oil for Older Porsches". Looks like the Porsche factory is recomending synthetic over conventional oil. Here is part of the article:

Deciding which motor oil is the
"right one" is probably one of the most debated areas of automo-/e theory — and you'll get 100 answers for every 100 people you ask. )me enthusiasts stick with one brand r decades, others buy whatever's on lie, and many experiment with a imber of different oils until they find ie they like, whether it's because of ist, reduced engine temperatures, or ime less tangible benefit. Porsche owners have another 'enue: They can turn to the factory for Ivice. Since January of 2001, Porsche is filled all new cars with Mobil 1 OW-I synthetic motor oil. That's a pretty impelling recommendation for owners newer Porsches, but what oil should i used in older cars? This Tech Forum II explore the factory's recommenda-
lions and offer some suggestions based on real-world experience.

Conventional or Synthetic?

Enthusiasts have been arguing over the advantages and disadvantages of synthetic motor oils ever since they came onto the market a few decades ago. Books have probably been writ-ten on the subject, but the Porsche line is simple: Synthetics are better. To quote Porsche's latest oil-related ser-vice bulletin, which covers all air- and water-cooled road cars from 1973-98, "Non-conventional basic oils have more favorable properties as com-pared to conventional oils." (Non-con-ventional refers to synthetic oils, con-ventional means mineral oils.) Not very strong words, but the company's actions speak much louder: Porsche no longer approves any conventional oil for any of these Porsches.
Hard-core oil aficionados will already know that what is generically called "synthetic" motor oil is actually two distinct types: synthetic and hydrocrack. For the rest of us, what's the difference? Conventional motor oil is refined crude oil, pumped out of the ground and distilled for use in car engines. Synthetic motor oils are made from a conventional oil base but con-tain added synthetic hydrocarbon lubricants (such as polyalpaolefins) to improve low-temperature lubrication

Posted by: reverie Jun 3 2004, 10:27 PM

Yes, Jake, that was many moons ago..

Posted by: grantsfo Jun 3 2004, 11:32 PM

I ran a 1.7 170,000 miles on Castrol 20-50 and it was still running strong. Ran a 2.0 with Castrol 20-50 120,000 miles no problems. Running Castrol Syntex 20-50 in my 1.8 for the past 12,000 miles no problems.

Posted by: phantom914 Jun 4 2004, 09:16 AM

OK Jake, stupid question:

Someone here said that they heard a long time ago that synthetics don't absorb heat as well. You said that Valvoline and Royal Purple yield lower oil temps. Wouldn't those two statements support eachother? I guess the real question is: do Valvoline and Royal Purple yield lower engine/head temperatures?


Andrew (I warned you it was a stupid question)

Posted by: Jake Raby Jun 4 2004, 10:01 AM

Some synthetics soak he up, but don't disspiate it well in our applications...

Not all synthetics are good. Valvoline and Royal Purple are by far the best for a Type IV.

Posted by: synthesisdv Jun 4 2004, 10:33 AM

so which RP for florida racing?

also, is swepco still the best in 901 tranny?

dr

Posted by: MarkG Jun 4 2004, 03:53 PM

Used 30w Kendall GT1 in my 911. I have seen 30W Castrol foam in air cooled VW engines when they are not run up to oprating temps for a reasonable amount of time, Kendall GT1 did not seem to have this problem.

Redline 10/40W in my Ferrari, but a lot of those folks also swore by Royal Purple...

Redline in my 240Z, Saturn and Hyundai over the years too.

Posted by: drew365 Jun 4 2004, 06:22 PM

I've used Valvoline 20/50 Racing Oil in all my cars for years. It has served me well. I've raced my 2.7 twin plug for 2 1/2 years without so much as a hiccup.

Posted by: cnavarro Jun 5 2004, 05:26 AM

I Royal Purple Racing Series (21 or 41) when I want the best oil possible. Both are detergent and rated for use on street engines, but have significantly more of their additive package than normal RP. Also use Mobil 1 0w40 and Delvac 1 5w40- both are excellent oils respectively, and Delvac is the cheapest synthetic around for it's quality, which is on par with Mobil 1. There are some rare and hard to find alternatives that are equally good like Castrol 5w60 and Motul 5w60, but at 15-20 dollars a quart, they are out of my price range for a daily driver. But then again, BWM M3s come with the stuff from the factory to combat high oil temps and thermal breakdown, so it's got to be good!

Charles Navarro
LN Engineering
http://www.LNengineering.com
Aircooled Precision Performance

Posted by: BGman Feb 1 2005, 09:19 PM

FYI- old thread...

But I found Royal Purple products at our local O'Reilleys auto parts store this weekend.
Apparently they are starting to stock them.