Oil change

[alexblack13]

CSS 20/60 semi sinth...

AB...

[Esprit2]

True racing/ competition oils are typically changed after each event. As a result of their short term use, they're normally formulated without the additives required for extended change intervals in street use. From a lubrication and anti-wear standpoint, they're more than adequate for use in your street car; however they should be changed every 500 miles or 3 months, whichever comes first.

On this side of the pond (North America), some oil companies use "Racing Oil" as a way of making high performance, High-ZDDP oils available to owners of high performance hot rod and specialty cars... oils that exceed API limits for ZDDP (NNWWSNM). To make the racing oils more appropriate for street use, some companies formulate their racing oils with full street additive packages. Mobil 1 0W-50 and 0W-30 Racing Oil, Valvoline VR1 Racing Oil (both mineral and synthetic) and Castrol Castrol GT Racing Oil all contain full street additives and can be used for extended oil change intervals. On the other hand, Valvoline VR1 NSL (Not Street Legal) Racing Oil does not and should be changed every 500 miles or 3 months, which ever comes first.

Nothing on the bottles indicates whether those oils are appropriate for extended street use, so it is up to the user to do the research and contact the oil company before choosing to use a racing oil in a street engine.

I don't know what the situation is in the UK or Europe, and I'm not familiar with Miller products; but I know I'd call and ask a few questions before choosing to use their Competition or Motorsports oils for extended drain intervals.

*~*~*
Castrol TWS Motorsport 10W-60 Synthetic Engine Oil (previously known as Castrol Formula RS 10W-60 and then Castrol Edge SPORT 10W-60 ), is an excellent, high-performance street oil. It also has a premium price, but it's excellent for high performance street engines that might also see occasional motorsports or high-speed lapping use.

BMW's private label, premium high performance 10W-60 synthetic motor oil, sold exclusively through BMW dealerships for it's M-series cars, used to be a private label re-brand of the same Castrol Formula RS 20W-60 which Lotus' TSB recommended for all 9XX 4-cylinder and V8 engines. And which was subsequently rebranded to, "Castrol EDGE SPORT 10W-60" and then to, "Castrol TWS Motorsport 10W-60".

BMW Motorsports 10W60 Synthetic = Castrol RS 10W60, changed to:
BMW Motorsports 10W60 Synthetic = Castrol Edge SPORT 10W-60, became:
BMW TWS Motorsport 10W-60 = Castrol TWS Motorsport 10W-60 (current, Fall 2011).

Regards,
Tim Engel

[UAB807F]

A very interesting post Tim, lots of info that I didn't appreciate before.

Personally I've never felt the need for a "Racing oil" although I became a fan of Mobil 1 synthetic when it first came out over here and have used it since. I don't know if that's a good or bad thing but the oil pressure seems to hold up even after moving from the previous 50 grade to the 40grade, which did surprise me a bit. (perhaps I don't drive hard enough.... )

Brian

[Esprit2]

The interest in using racing oils (or motorcycle oils) usually stems from a concern over adequate levels of ZDDP for older engines with flat tappet cams and vintage metallurgy. With modern oils, the ZDDP level can vary by viscosity grade, and it's no longer safe to presume a particular brand or trademark will be safe across the board.

In North America, almost all Mobil 1 street oils are reduced ZDDP oils, with phosphorus levels (anti-wear, zinc isn't of interest) varying from a low of 650ppm, to 800 for most, and 1000ppm for a select few. 15W-50 is the ONLY street grade of Mobil 1 that meets the API limit of 1200ppm.

If you use 15W-50 during the summer and have great results with it, it's not safe to assume you will have the same results with a lighter viscosity Mobil 1 for the winter, as ZDDP content will be significantly lower (not that many folk around here would consider driving their Lotus in the Winter... but you get the point).

On the other hand, Mobil 1 Racing Oils have approximately 1750ppm Phosphorus/ 1850ppm Zinc in the form of ZDDP, way above the API's 1200 limit. So they're marketed at retail as racing oils without API certification, but with a full compliment of street additives for extended drain intervals as a back door way of giving those owners of older high performance engines the oil they need... "Not recommended for street use" (only because it exceeds the API maximum limit for street oils, NNWWSNM).

Also, the old Mobil 1 20W-50 that Lotus recommended back in the day for older 2nd Generation 9XX engine cars, and that worked so well, has 1600ppm Phosphorus/ 1700ppm Zinc, again over the API's limit. So it's no longer marketed in North America for use in cars, but it's been re-branded as 20W-50 V-Twin Motorcycle Oil and is still available. Great stuff. You just need to shop in the motorcycle aisle.

That's what Mobil 1 sells in North America, I don't know that they sell the same recipes in other markets where API isn't the dominant agency. I'm just using M-1 as an example since you brought it up, and you should presume all oil companies do the same selective blending to some degree or another. Check ZDDP content by brand, trademark and grade before you breathe easy.

Regards,
Tim Engel

[bcmc33]

My new tall block engine has Millers high ZDDP running-in oil in it at the moment.
It's done the 50 running-in cycles (as per Rohan's instructions), and will be retained for 500 miles when I shall replace it with the semi-synthetic stuff.

[UAB807F]

Yet more useful insight Tim, which is appreciated.

How do you find out these levels ? The last oil I bought (a 10/40 but not Mobil 1 incidentally, it's a short term oil ) didn't give any such info on the can, just the usual grade approvals so I'm none the wiser. But I would like to know how to find out for when it's replaced at the end of the year.

[Esprit2]

Not to pick on Mobil 1, they are just the easy target because they're the most open oil company about publishing what's in their oils. Most other oil companies don't talk about it, and certainly don't publish anything.

Some companies are totally "green" and don't market high-ZDDP oils (above 850ppm), others market select grades with higher levels of ZDDP, but still within spec limits, others are motorsports oriented and sell a full line of high ZDDP oils. All meet the same industry standards, so there's nothing on the label to alert you to what's in it. You need to shop and do your research... call the tech center.

Here's the Mobil 1 product line marketed in North America, simply because it's readily available. Notice the broad range of ZDDP levels... you can't assume all Mobil 1 is created equal, and that's typical of all main-stream oil companies' product lines.

Mobil 1 grades and ZDDP levels in North America:

Street Automotive Oils
Phos. / Zinc
650p. / 750z Advanced Fuel Economy 0W20 & 0W30

800p. / 900z Extended Performance 5W20, 5W30 & 10W30
800p. / 900z 5W20, 5W-30, 10W30
800p. / 900z ESP Formula M 5W40
800p. / 900z ESP Formula 5W30

1000p / 1100z 0W40 - Porsche & some Euro cars, HT/TS apps.
1000p / 1100z 5W50 - Porsche HT/TS apps.
1000p / 1100z High Mileage 5W30, 10W30, 10W40 (SL / SJ).

1200p / 1300z 15W50 - HT/TS, and flat tappet applications.

Motorcycle Oils
1200p / 1300z Racing 4T 10W40 - Motorcycles (SM / SJ / SH)
1600p / 1700z 20W50 V-Twin Motorcycle Oil (SJ)

Racing Oils
1750p / 1850z Racing 0W30 & 0W50 (not API certified)

More phosphorus is what we want for anti-wear in vintage engines, zinc just comes along for the ride in ZDDP. Zinc is not the key, it's just the first word in the long chemical name (Zinc Dialkyl Dithio Phosphate).

Regards,
Tim Engel

[Esprit2]

(Snip)... How do you find out these levels ? The last oil I bought (a 10/40 but not Mobil 1 incidentally, it's a short term oil ) didn't give any such info on the can, just the usual grade approvals so I'm none the wiser. But I would like to know how to find out for when it's replaced at the end of the year.

There isn't a simple one-stop website or library of published oil/ ZDDP data. If you do a web search for ZDDP content in oil, you'll get a lot of hits you can sift through. Unfortunately, oil specifications are a moving target and a lot of the search hits will be old info. Sorting out what's current and what's ancient can be a problem.

ZDDP is also a popular topic on some motorsports and Marque forums, and you can often benefit from someone elses research. Unfortunately, it's not been much of a topic on this Elan forum, so you'll have to search elsewhere.

The simplist approach it to call the corporate headquarters for the oil you're considering using, ask to speak to a Tech Rep, and ask what the ZDDP level is in the oil you plan to use, as well as other trademarks and viscosity grades they sell. If they're helpful and forthcoming about info you need for your vintage car, then they're a company you'll want to do business with going forward. If they won't quote numbers and just say, "Our oils are all adequate for your car, trust us", then you might want to consider using a different brand of oil.

On the other hand, some oils just have stellar reputations. Castrol, for instance, is about as tight-lipped as any oil company out there... they won't state or write ANYTHING about what's in their oils beyond "Trust us". Normally, I'd look for another company at that point; however, Castrol TWS Motorsport 10W-60 Synthetic Motor Oil is about as good as you can get. I'd use it... "IF" Castrol marketed it on this side of the pond... they don't.

Some motorsports magazines and club/ Marque publications also print comparative oil performance test articles from time to time that can be quite revealing. Copies of some of them also surface on internet searches occassionally.

Clearly there's no one, simple place to find the tabulated info you seek. You just need to take an interest since it affects your cars, and keep your ear to the ground. Be proactive and contact the oil company in question, and post what you learn for everyone else's benefit. Banding together and sharing info is our best defense.

Regards,
Tim Engel

[Esprit2]

Oops... double post deleted.

Tim

[Esprit2]

I just looked back over what I've posted lately... sorry about burning all the bandwidth.

I'm a mechanical engineer, not a mechanic; but I do all my own mechanical work and also help local club members rebuild their engines, transaxles, etc. A few Twin Cams, but mostly 907 & 910 engines.

In recent years, I've been replacing a lot of tappets due to surface spalling (wear, surface cracks, chunks missing) and cracking side skirts (a few have split in two in my hands). I don't have lab results relating the failures directly to low ZDDP, but I find it interesting that the occurrences of something that never used to be a problem now correlate closely with the introduction of low ZDDP oils. Hmmm...

The 907 and early 910/912 chilled iron tappets are the same Lotus P/N as those used in the Lotus Twin Cam, so 1st generation Lotus owners should also be interested in the problem. Later 910/912 trappets changed to steel, but I've also seen problems with them as well.

Without lab results I'm more paranoid than knowledable, but I choose to err on the side of over-compensating. I use high-ZDDP oils in my older fun-cars, and very high-ZDDP racing oils in a few that tend to get flogged harder. None of my own tappets have failed. I've not started a crusade, but when the subject comes up I suggest that other's do the same... use high-ZDDP oils. But it's your choice.

Regards,
Tim Engel

[nebogipfel]

Bit of a tangent but does anyone know if any of the readily available oil additives contain ZDDP?

[Esprit2]

Many do, just Google, "ZDDP oil additives". Off the top of my head, the following all contain ZDDP plus Molybdenum DiSulfide:

ZDDPlus
http://zddplus.com/

CamGuard
http://www.aslcamguard.com/

Redline Engine Oil Break-in Additive
http://www.redlineoil.com/Products.aspx?pcid=1

Eastwood ZDDP Additive
http://tinyurl.com/43kved6

Comp Cams' Comp 159 Oil Additive
http://tinyurl.com/3lky482

Rislone Oil Supplement with ZDDP
http://www.barsproducts.com/4401.htm

Regards,
Tim Engel

[UAB807F]

I just looked back over what I've posted lately... sorry about burning all the bandwidth.

Hey, there's no need to say "sorry", they are very detailed posts and much appreciated. In fact I'm wondering if we ought to have a separate thread because the more I look at this, the more I find that may be applicable to our cars.

Ten minutes googling and some of the research I find is quite concerning; "more isn't better, more can be as bad as not enough" that's paraphrased but basically the curves of wear prevention peaked and then fell away as more phosphorous in the form of ZDDP was added. The claim was that at 0.2% it began grain boundary attack & resulted in camshaft spalling. As an (ex) metallurgist I can appreciate the potential effects of minor corrodent levels and that fact alone makes me very wary of a DIY oil cocktail where I don't know the starting point.

And references to replacing phosphorous compounds with boron based compounds for EP lubrication could (note "could") mean that we are all worrying about nothing and simply picking up on the fact that the formulations are changing. I don't know and have no axe to grind either way (with or without ZDDP ) Enough interest for a ZDDP thread ?

[rmd24]

Well, what a can of worms I opened with a simple question about oil change intervals! I suppose I should have known that few questions are actually that simple, but what a lot of useful, and to me previously unknown, information has resulted.
So, it looks like Millers CSS 20/60 as a possibly better alternative to the original Millers Classic 20/50 particularly as they say that they are commited to maintaining higher levels of ZDDP in all their Classic and Motorsport oils.

Roger.

[ardee_selby]

Well, what a can of worms I opened with a simple question about oil change intervals! I suppose I should have known that few questions are actually that simple, but what a lot of useful, and to me previously unknown, information has resulted.
So, it looks like Millers CSS 20/60 as a possibly better alternative to the original Millers Classic 20/50 particularly as they say that they are commited to maintaining higher levels of ZDDP in all their Classic and Motorsport oils. Roger.

There is their "half-way house", the Millers Classic Sport 20/50 semi-synthetic. (Unless that's what you are already using). You pays your money, takes your choice: From the website, in order:

Classic 20w50
-------------
DESCRIPTION: Mineral based engine oil for classic engines.High quality solvent refined base oils with latest technology performance additives and shear stable viscosity index improver.

PERFORMANCE PROFILE: API SJ / CE

TYPICAL CHARACTERISTICS:
SAE Viscosity Grade ... 20w50
Specific Gravity @ 15?C ... 0.890
Kinematic Viscosity @ 100?C ... 18.1cSt
Kinematic Viscosity @ 40?C ... 159cSt
Viscosity Index ... 115
Pour Point ?C ... -23
Flashpoint ?C ... 228
Cold Crank Viscosity ... 9,500cP

Classic Sport 20w50
-------------------
DESCRIPTION:
Semi synthetic engine oil for classic performance and sports car engines.
TYPICAL CHARACTERISTICS:
SAE Viscosity Grade ... 20w50
Specific Gravity @ 15?C ... 0.888
Kinematic Viscosity @ 100?C ... 21.9cSt
Kinematic Viscosity @ 40?C ... 170cSt
Viscosity Index ... 150
Pour Point ?C ... -23
Flashpoint ?C ... 228
Cold Crank Viscosity ... 9,265cP

CSS 20w60
-----------
DESCRIPTION:
Very high performance competition semi-synthetic engine oil for older engines, based on highest quality performance additives and shear stable viscosity improvers in synthetic and mineral base.

TYPICAL CHARACTERISTICS:
SAE Viscosity Grade ... 20w60
Specific Gravity @15?C ... 0.888
Kinematic Viscosity @100?C ... 24.0cSt
Kinematic Viscosity @40?C ... 170cSt
Viscosity Index ... 155
Pour Point ?C ... -23
Flashpoint ?C ... 210
Cold Crank Viscosity@ -20?C ... 9,500cP