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MG Midget and Sprite Technical - which oil ?

Good Morning all

1978 midget 1500. The manual says 20/50 oil when doing a service. Which is the most reasonable one to get because everybody seems to do one.... even Tesco. I dont want rubbish but at the same time I am not going to pay over the odds if a cheaper alternative will do.

What experience has everybody got of different types?

Thank you


Blaggard
SR Blagden

Using a 10/40 won't harm the engine - you may find oil pressure is a little lower, and the engine leaks a bit more.

If you use motorways for long distances, you might want to think about an oil cooler - this will lower oil temp and maintain pressure.

A
Anthony Cutler

Hi, Halfords do stock a 20/50 classic oil (green metal tin) which I have used in the past. Also Comma and Millers are other names that spring to mind.

HTH
Mark
Mark Whitmore

I use the 20/50 from Halfords.. even smells the same as it did 40 years ago
David Cox

I use 20/50 Halfords or 20/50 Casrol every six momths

I used to use Mobil 1 (15w/50 Motorsport) once a year with my previous classics and will probably go back to it for next annual service

I done tens of thousands of miles with it before with no problems

Mobil 1 is now Extended Life 10W-60

- http://www.mobil-1.co.uk/cms/extended-life-10w-60.aspx
Nigel Atkins

Asda 20W/50 is on sale at my local store at £1.69 per litre. (The buggers have stopped selling the 5 litre canisters) :(

I buy three or four any time I'm in there since I discovered they had downgraded sales to 1 litre bottles only.

Six in stock in my garage at present for the pre-summer oil change & service.

The oil is fine, my car has been using this and the green tin Halfords oil ever since...
Bill 1

Got my 20/50 Comma from my local parts shop, £14,but the can isn't as pretty as the £22 green Castrol tin.
Keith Davies

I wouldn't recommend using a 10/40 or an expensive Mobile 1 oil. I tried once and found that the engine leaked like a sieve and was rattly, especially when first starting up. I just don't think it suited these older engines. I certianly wouldn't go for a thinner oil for a 1500 with known big end bearing problems.

I have used Penrite, Comma and the Halfords 20/50. Although I have also use the very cheap Asda oil as mentioned by Bill. Bill knows about this sort of thing and I also found the Asda oil to be just as good as the more expensive stuff. I think the kep is regular oil changes. I would rather use a cheap oil, changed every 6 months, (3000 miles) than go for the expensive oils and expect it to fester in there for two years or more!
Guy

Totally agree Guy no point using expensive stuff like Mobil 1 if your engine isn't up to much :)

I would still avoid cheap oil (inexpensive or 'sale' prices on oil, yes) even when changing ever 6 months

Some think a (full car) service is an occasional oil change so the beeter the quality the better

Others think why change the oil for the very miles they do (in a decade, or the few years they keep it before they get fed up with the car being unreliable!)

I'm not bothered about the minor increase it noise at my car doesn't have any soundproofing at all except the very cheap thin 'club' carpets and I didn't notice any increase in leaks but I wouldn't have used it if I had an real leaks

It cost £24 with £4 back with an Argos card for 4 litres I think when I first started using it

I've never had a Triumph 1500 engine but I have seen on some Triumph specialist that they recommend Mobil 1
Nigel Atkins

I regularly used the Halfords oil for older cars, in the red container, in two cars.One a 1500 Midget and another with a Ford Xflow engine, for about 10 years without problem, but occasionally I would get the 1500 "death rattle" on start up in the Midget, if the engine had been not run for a few days.

Last year I changed to the Halfords "Classic" oil and as yet the rattle has never been present at all, even after not using the Midget for a few weeks.

I don't know why this is happening, could be the viscosity of the oil (although it is the same as that of the oil in the red container) prevents total drain back of the filter or it coats the bearing surfaces in some way which cushions them on initial start, but I am quite happy with the situation as I have tried just about everything to minimise this problem over the years!

Halfords stuff in general used to be a bit ropey but no complaints about this oil.

JB Anderson

I run Castrol 20/50 oil. I figured the guys who designed the car know more than I do so I'll trust their expertise.
Clive Reddin

Whatever you use make sure it contains zddp.

Peter
P Burgess

Hi Peter what do you think the consequencies of not using an oil containing zddp would be please?
Robert (Bob) Midget Turbo

I use Castrol XL 20/50 in my 1500, I work on the principle of using the best oil I can afford because if it reduces wear it'll be cheaper in the long run. As I’m not a chemist I trust (perhaps foolishly) named brands, and view reports of people using cheap or no name brands a bit like John Gummer eating burgers to prove they're safe. He may not have dropped down dead immediately but could he really be sure it wouldn't give him CJD sometime in the future? Better safe than sorry.

Bob
R.A Davis

Blaggard,

I have been using Castrol 20/50 GTX for over 40-years without issue. We have a club member here (USA) who is a chemical test engineer who conducted his own test on available motor oils, and recommends oils formulated for diesel cars of our classic engines because of the higher zddp content. Further, here is a link on "zddp" from the Volvo Club.

http://www.volvoclub.org.uk/castrol_with_zddp.shtml

Regards,

Larry C.
Larry C '69 Midget

Hi larry

I find this a staggering statement that modern oil such as Mobil one would break down prematurely. Do Mobil know this?

""Inadequate anti-wear additive (ZDDP) and the oil film between moving parts breaks down prematurely, resulting in metal to metal contact and damage to reground or new engine components particularly on run-in.""

Many years ago I had an engine built by Osselli. They INSISTED that I should run the engine in on very cheap oil, why? because quality oils such as mobil or shell helix were far to good and did not allow the engine to bed in!

This would suggest that zddp was no longer necessary???
Robert (Bob) Midget Turbo

Bob, in short, the ZDDP is needed to lube the cam lobes as the pressures which occur here are extreme and break up the oil. Diesel oil has a lot of ZDDP, but also a completely different set of other additives, so it is usable but not the best.
The amount of zddp and other additives such as detergents need to be in balance, because they can contradict or even cancel each other out. So just adding a lot of Zinc additives seldom has the expected effect.

In short: Use a classic oil like Millers or Castrol classic or an older formulated oil, often the case with cheaper oils.

The zddp is gradually lowered because it damages catalysts in exhausts
Alex G Matla

But modern engines have camshafts, why do they not suffer premature wear?
Robert (Bob) Midget Turbo

according to Castrol's website, their GTX that we have trusted for many years does not have zinc in it any longer (at least in the US):

http://www.castrol.com/liveassets/bp_internet/castrol/castrol_usa/STAGING/local_assets/downloads/p,q/psd_gtx_usa.pdf

and their GTX High Mileage doesn't even indicate one way or the other about it (making me doubt it):

http://www.castrol.com/castrol/liveassets/bp_internet/castrol/castrol_usa/STAGING/local_assets/downloads/p,q/pds_gtx_high_mileage_usa.pdf


While ZDDP levels have been gradually reduced starting with SG oils in 1988, the latest SM designated oil with the nearly total elimination of ZDDP. As a result, the oil you buy that meets the latest API spec of "SM" won't have what you are used to getting in it.

If you are shopping for oil, the ideal API rating that you want is "SG", anything that is claimed to meet an API rating later than that won't have the ZDDP levels we want, which is 1200ppm.

I found this from a quick web search on the subject of "ZDDP":

There are still a few oils on the market that have adequate levels of ZDDP.

* Shell Rotella T which is a conventional (mineral-based) oil that was originally formulated for diesel engines. Rotella T still contains 1,200 parts per million ZDDP, according to Shell – which is as much as five times the amount found in other oils meeting the "SM" API rating. Don’t sweat it that Rotella was/is “for diesels.” It’s also an excellent choice for older, non-emissions controlled engines with flat tappet cams that need their ZDDP. Rotella’s also modestly priced and readily available at most any auto parts store. Shell also markets a synthetic version of Rotella that offers even more protection – as well as longevity and a 5W-40 viscosity for those who operate their vehicles in colder climates. Standard Rotella comes in a heavier 15W-40 blend.
* Another choice – in a full synthetic – is Amsoil which carries a line of oils with ZDDP in popular viscosities such as 10W-40 and heavier 20W-50.
* Redline oil is also still fine for older engines with flat tappet cams. Unfortunately, both Amsoil and Redline can be hard to find at your local store; but if you plan ahead, you can order a case from any one of multiple suppliers online and just keep a stash on hand.

I also found this:
http://www.macysgarage.com/myweb6/ZDDP.htm


There are those who suggest the ZDDP is less needed after an engine is fully broken in. But one thing that is absolutely clear is that a new cam MUST have sufficient ZDDP during break-in or it will quickly fail (most cam manufacturers now have warnings to this effect included in their information, by now).


Hope this helps,
Norm
Norm Kerr

My cams must be ++++ed then? I sincerely hope not.

I must admit that I had got the impression that zddp was a cheap way of giving oil valuable properties that in modern oils come at a high cost. Bit like lead does in fuel for increasing octane rating. High octane ratings without the use of lead are achievable but cost considerably more. I thought the same was the story with zddp. Not convinced either way?
Robert (Bob) Midget Turbo

Interesting piece here;

http://www2.mgcars.org.uk/cgi-bin/gen5?runprog=mgbbs&access=&mode=archiveth&subject=97&subjectar=97&thread=20061009022558843
Alex G Matla

The link is not working? mate
Robert (Bob) Midget Turbo

Robert,

As it was explained to me, think "flat tappet" vs "roller tappet" as it relates to "zddp" and our "classic" engine. MOSS (USA) make an additive, but not sure if it's worth the trouble?

http://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=65940

More on the "flat tappet world".

http://synmaxperformancelubricants.com/PDFs/SynMax_UNV_API_Modern_Street_vs_Classic_HotRod_MotorOils.pdf

Regards,

Larry C.
Larry C '69 Midget

Hi Larry I am simply playing Devils advocate and trying to see if someone can create a constuctive arguement to support the additive.

So far no one has explained that an oil such as mobil 1 or Shell helix that is such a good lubricant that it will not allow an engine to bed in will somehow be a poorer performer than a lubricant used 60 years ago. would like to ask shell or Mobil why their oil is not as good as zddp?

What would they say?

When I have search the web for information on the subject I have only found manufacturer support (and why not) or someone simply repeating that info.
Robert (Bob) Midget Turbo

Hi Bob

My understanding is the engines are developed to withstand the lack of zddp using different materials and hardening perhaps.

here is a link to Millers oils, btw I do not use Millers :)

http://www.millersoils.net/1_Millers_frame_CLASSIC.htm

Peter
P Burgess

You all need to set half an hour aside and read Martin Williamson's truly amazing piece of work on Engine Oil for MG cars. Martin is a regular contributor on the MGOC web site BBS and oil is his business. Find it here http://www.kewengineering.co.uk/Auto_oils/index.htm

This what he says about ZDDP (AW means AntiWear Additives)

"AW is usually ZDDP or to give it its full name, Zinc DialkylDithioPhosphate. Owing to the use of exhaust catalytic converters (exhaust gas aftertreatment) and the environmental push to limit Zinc and Sulphur, newer oil formulations have reduced levels of Zinc. Consequently there has been some discussion to suggest that this may affect the wear rate of the flat topped cam followers used in older engine designs.

The fact is that the levels of ZDDP in modern oils are still sufficiently high enough to protect most classic engines, and today’s oils still have as much as 4 times the amount of ZDDP by comparison to oils formulated in the early 1960s when the A and B Series were first used in production cars. Whilst newer engine designs differ from older designs, the newer oil formulations more than compensate for wear protection by having differing formulations for AW protection. "

There is so much information on this site I can't possibly distil it here. Have a read.
Mike Howlett

Mike,

Thanks for that, good information there in easy to understand terms. While my professional background is in engineering, I do not have an extensive background in industrial chemistry. Enough perhaps to know to seek advice for a particular application.

Robert,

I think the (above) SynMax attachment delves into your question pretty well. Personnally, I will continue to use mineral based Castrol 20/50 GTX with no additional additives.

Regards,

Larry C.
Larry C '69 Midget

I thought I would give Mobil the opportunity to defend themselves here and asked them to comment on the assumption that their superior oils were not up to the task of protecting older engines ith flat Tappets.
Their answer was as I expected here it is in full.

""What you wrote is incorrect altough there is a part of truth.

Due to the introduction of diesel particulate filters or DPFs, the oil companies have been forced to introduce the so called "low ash" engine oils which are intended for DPF fitted cars as unburned ashes from the oil in the exhaust gas shorten the DPF lifespan.

Since ZDDP is a major contributor to the ash in the oil, its use in low ash oils formulation has to be significantly (but not completely) reduced. Mobil 1 ESP 0W-40 and Mobil 1 ESP Formula 5W-30 are low ash oils so they contain somewhat less ZDDP than the other Mobil 1 oils, however alternative ashless antiwear additives are employed to compensate this.

The other Mobil 1 oils (Mobil 1 0W-20, Mobil 1 New Life 0W-40, Mobil 1 Peak Life 5W-50 and Mobil 1 Extended Life 10W-60) are more traditional formulas with an adequate ZDDP treat in order to keep the wear rate as low as possible.

I hope this clears your doubts.

Best regards and Happy Easter.""

So either the oils have a different wear reducer or they have zddp .
That clears that up I think.

Robert (Bob) Midget Turbo

Hi Bob

The zddp I think is required for older engine materials/hardening hence reatining the zddp for older stuff, if the new stuff protected the old engines the zddp would not be required and wear would not occur in older stuff.

Older stuff such as A and B series with large oil gallery bores need thickish oil to function well, the thinner oils tend to run very low pressures when hot.

If it wasnt needed in older stuff Mobil wouldnt make it as there would be no need?

Peter
P Burgess

This thread was discussed between 19/04/2011 and 21/04/2011

MG Midget and Sprite Technical index

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