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Dudly
06-12-2008, 08:44 AM
Hello all-
I was wondering what the consensus was regarding motor oil? Am I wrong or do I recall an issue with modern oils where a component or additive was removed from oil that was essential for older motors?

What is everyone using?
Are synthetics appropriate?
Am I thinking too much?

Cheers!
D
79 Spitfire

Mickey Richaud
06-12-2008, 08:48 AM
Oh, man, Dudly - this has been much discussed!

Bottom line is that most are worried about the reduction of zinc (ZDDP) in current oils. Some are using additives to replace; others are looking for oils that still have "adequate" amounts of ZDDP. Shell Rotella T is the one that I use in my TR8. Still using Castrol 20/50 in the MGB.

Check some of the prior discussions using the search function - plenty to keep you busy reading!

TR3driver
06-12-2008, 08:50 AM
Still a hotly debated topic, with plenty of FUD and not a lot of facts.

I've been using Valvoline full synthetic for quite a few years now in all my cars, and am quite happy with it.

Worth noting perhaps that I grabbed the wrong bottle when I topped up the family wagon for a recent 5000+ mile trip, and oil consumption went up markedly with Mobil 1. Seemed to settle back down after I started with the Valvoline again though. Odo turned 200,000 during the trip.

RobT
06-12-2008, 09:05 AM
Using Castrol 20W50 full synthetic plus a ZDDP additive.

Since this topic has been done to death, here is a new spin to the debate that we can add:

I have heard that switching to synthetic oils can exacerbate oil leaks. This makes sense to me as synthetic oil is supposed to be more slippery and can sneak past the seals more easily.

BUT I have also been told that over time, the leaks diminish as the seals "get used to" the different oil. This sounds real fishy to me - anyone else heard this or is it just a urban myth?

Rob.

TR3driver
06-12-2008, 09:33 AM
I have heard that switching to synthetic oils can exacerbate oil leaks. This makes sense to me as synthetic oil is supposed to be more slippery and can sneak past the seals more easily.

BUT I have also been told that over time, the leaks diminish as the seals "get used to" the different oil. This sounds real fishy to me - anyone else heard this or is it just a urban myth?
As I understand it (which may or may not have anything to do with reality), "dinosaur juice" naturally causes seals to swell a bit. Pure synthetic oils don't. So, they have a "seal sweller" additive.

Obviously, different brands can have different sweller additives; so I suppose it might take some time for the new additive to work.

But I've never noticed an increase in consumption when switching from conventional to the Valvoline synthetic; in fact in one case it lowered consumption considerably. That plus my recent experience with the Mobil 1 tells me that all synthetics are NOT created equal.

vivdownunder
06-12-2008, 10:05 AM
Yep, that's suss Rob, since there's not terribly much brainpower in a gasket or seal to adapt "as required".

I'm a stickler for Penrite in the older cars simply because their main business is in providing lubricants for vehicles of yesteryear. They're keen when contacted, whereas others don't seem to know a TR from a toothbrush, and you soon get flung when you seek advice for anything on wheels over about two decades old.

Regards,

Viv

billspit
06-12-2008, 10:20 AM
The oil situation is changing all the time and the companies aren't too free with the info. The diesel oils that everybody were using (Rotella T mainly) have had some of the zddp removed since the discussion began. The new CJ will not have the full level and The SM oil is due to be changed in the next year or so. SM oil isn't suitable either. A lot of folks are dissing the zddp additive, but are a little kinder to the AC Delco EOS stuff. Why can't somebody make a dino oil with the dang zddp, without trying to charge $6 a qt.

Castrol is now making a "synthetic" oil that is designed for classic cars that has the full amount of zddp. I am going to try that once I get the new motor running. I will use Brad Penn break in oil for the 25 minute break in. Followed by some otehr oil I haven't decided on with the Crane additive. Eventually ending up with the Castrol.

There are a lot of differences with synthetics. There was even a lawsuit over it. Go to Bob Is The Oil Guy (BITOG) and you can read about it for several days.

And it is possible to get too much zddp if you are adding it to oil that already has it. Too much is not better.

Dudly
06-12-2008, 10:53 AM
I've started using a full synthetic in my GTI and have been very pleased. Does anyone have any experience with the Red Line brand?

RonMacPherson
06-12-2008, 01:19 PM
I use and recommend Yamalube. Yamaha motorcycle oil. Still available in the early formulations. Last time I bought it was less than 5 a quart.

Dudly
06-12-2008, 01:45 PM
Thanks Ron, I never thought of that.

tosoutherncars
06-12-2008, 04:49 PM
I have heard that switching to synthetic oils can exacerbate oil leaks. This makes sense to me as synthetic oil is supposed to be more slippery and can sneak past the seals more easily.

BUT I have also been told that over time, the leaks diminish as the seals "get used to" the different oil. This sounds real fishy to me - anyone else heard this or is it just a urban myth?
Rob.

As a Mercedes guru friend of mine explained to me, it's not so much that dino oils swell seals. It's that synth oils, as well as being 'slicker' have stonger detergent properties. So on older engines, synth may wash out swarf or sediment that has built up, particularly where there has been a slight leak in the past.

As to whether the additives may eventually swell the seals, causing the leaks to stop? No idea... sounds like wishful thinking to me, but I suppose stranger things have happened!

Trick6
06-12-2008, 08:35 PM
Red Line 20w50 is my oil of choice. Not cheap. I change it once a year at the end of the season (4-5000 miles maybe). I prefer to leave the car sitting over the winter with fresh oil in the sump. No runs, no drips, no errors.

redz350
06-16-2008, 04:51 PM
Brad Penn 20W-50 racing oil has the correct amount of ZDDP. It is the former Kendal formula, befor Kendal was bought out.