Castrol GTX

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Post by ozscim » Sat Jun 15, 2019 8:07 am

Hi all from OZ,

Quick question, is Castrol GTX 15 -50, suitable for an Essex? I remember using it for many years in my early Fords.

The reason for the question , is that a local supplier is offering 5Ltrs for $10.00 which equates to 5 UK pounds!!!

Worth buying????

Neil.



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Post by efi_sprintgte » Sat Jun 15, 2019 8:11 am

15W50 viscosity is fine.

What spec is the oil?


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Post by ozscim » Sun Jun 16, 2019 3:04 am

Hi, thanks for the reply,

This is taken from the Australian Castrol website, not sure if it is what you were asking!

Typical Characteristics
Name Method Units Castrol GTX High Mileage 15W-50
Density @ 15C, Relative ASTM D4052 g/ml 0.873
Viscosity, Kinematic 100C ASTM D445 mm²/s 17.7
Viscosity, CCS -20C ASTM D5293 mPa.s (cP) 5700
Ash, Sulphated ASTM D874 % wt 0.8
Pour Point ASTM D97 °C -36
Flash Point, PMCC ASTM D93 °C 199
Viscosity, Kinematic 40C ASTM D445 mm²/s 137
Viscosity Index ASTM D2270 None 143
Product Performance Claims
API SN

Cheers Neil.



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Post by efi_sprintgte » Sun Jun 16, 2019 7:19 am

API SN will be fine


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Post by Old and Slow » Sun Jun 16, 2019 9:39 pm

I thought SN was low in zinc, and nothing higher (alphabetically) than SL should be used in pre-2000 engines?


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Post by ozscim » Mon Jun 17, 2019 10:39 am

Hi, All

To buy, or not buy, that is the question!!!!

Cheers Neil.



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Post by GeoffTE » Mon Jun 17, 2019 11:49 am

Old and Slow wrote:
Sun Jun 16, 2019 9:39 pm
I thought SN was low in zinc, and nothing higher (alphabetically) than SL should be used in pre-2000 engines?
That is my understanding too. I’ve been doing a bit of research on suitable oils for older engines and it can be very confusing. As many opinions on which oil is best as there are oils. However the consensus is that the zinc content of the oils is important to minimise wear. Zinc content, ZDDP,is measured by ppm and this should be between 1000 and 1400 ppm for best protection. This can vary for a particular brand according to the viscosity. A SL category oil has a ZDDP level of over 1100, whereas a SM oil is a little over 800ppm. Personally I use Valvoline VR1 20/50 in SAR as well as the Elan which has a ZDDP of 1200. I think GTX did have a high zinc content but I’ve read that in the latest version the zinc content has been lowered because the catalytic converter can be affected. Don’t know what the latest value is. All this is just my opinion based on what I’ve read. This will probably kick off a disputed debate :w :lol:


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Post by scimjim » Mon Jun 17, 2019 12:03 pm

Copied from Hemmings dated 2012

There has been a lot of confusion in the last few years about the lowering of zinc and phosphorus levels in modern oils and how these lower levels relate to classic and performance engines using standard flat tappet lifters – that is, just about every car built before the Eighties. The concern involves the use of the new lower zinc/phosphorus-content ILSAC (multi-viscosity) oils, readily available on shelves at auto parts stores everywhere, and how compatible they are with these older engines.

When anyone mentions zinc, they are actually referring to zinc dialkyldithiophosphate, a compound invented by Castrol for use in mineral-based oils or zinc di-thiophosphate (ZDTP), which is normally used in synthetic oils. Both have been used as an anti-wear ingredient in engine oil for many years. The zinc and phosphorus ingredients appear to be most effective when they are used together. ZDDP/ZDTP is one of many additives that are put into conventional motor oil to improve its lubrication qualities. Other ingredients such as boron and molybdenum are also added as lubricant enhancers.

What was discovered through oil testing by several engine component manufacturers is that many older engines experience a short period of time during engine start-up where critical lubrication is insufficient between metal-to-metal lubrication points when using modern oils with reduced amounts of ZDDP/ZDTP. These same enhancers unfortunately have their downside: The phosphorus in this compound creates carbon buildup in engine bores and valvetrains, and both compounds can also lead to the early demise of catalytic converters. For this reason, the industry has been phasing out zinc and phosphorus levels since 1994, when the American Petroleum Institute’s SH designation became the industry standard, and levels have been further reduced in each subsequent API rating for engine oils. Manufacturers have tried adding more boron to offset the effects of the reduced zinc and phosphorus levels; however, the dry start protection does not measure up to those using more ZDDP/ZDTP. This has opened up a whole new market for zinc/phosphorus additives for oil and many camshaft and engine manufacturers now recommend that an additive be used in initial break-in and for regular use.

All engine oils are rated for viscosity by the SAE as well as additive content by the API; passenger car ratings are two-letter designations that start with “S.” Heavy-duty or off-road equipment ratings start with “C.” The current API oil rating for passenger cars (gasoline engines) is SM and for trucks (diesel engines) CJ-4. Within these designations, you can determine how much zinc and how many other chemicals are present in the ILSAC (multi-viscosity) oils. These levels do not apply to straight-weight oils. If levels in the ILSAC oils are too high for the API specification, they cannot be rated for the current specification unless the container specifies “for racing or off-road use only” or “for use in classic cars.” This has caused oil companies to reduce levels of many additives, including zinc and phosphorus, to the required maximum in order to meet the current specification. Listed here are the current specifications for maximum amounts of additives to achieve the API ratings. P is phosphorus, Zn is zinc, and B is boron. Each figure is total parts per million of additives. These can also be roughly expressed in percentages by multiplying by .0001 (1301 PPM = .13 percent, 994 PPM = .099 percent)

API........P..........Zn..........B
SJ.......1301.......1280.......151
CI-4.....1150.......1374.......83
SL........994........1182.......133
CJ-4.....819........1014.......26
SM.......770.........939.......127

Most engine and engine component manufacturers recommend zinc and phosphorus content of more than 1,200 PPM for break-in; in fact, many will void warranties on camshafts or crate engines if this minimum is not found in the oil sample you supply when returning broken parts for warranty. For this reason, many manufacturers produce their own zinc additives or oils with supplementary zinc included; GM even offers its own break-in oil with additional ZDDP. With respect to readily available oil, you can see from the chart that, if you can find oil still on the shelf rated SJ or SL, you can use them, but you are right on the cusp of voiding a warranty. New SM oils are just not going to cut it unless they have a zinc additive to boost the rating and one of the zinc supplements should be used with these oils or oils containing additional ZDDP additives are recommended. Some enthusiasts have recommended using commercially rated CI-4 15W40 diesel oil to meet the zinc and phosphorus additive requirement; however, CI-4 is an old specification and hard to locate. You can see that the CJ-4 specification that now supersedes it is well below acceptable levels. Our best recommendation is that you contact your oil supplier for exact additive contents. Many straight-weight oils do not have to meet the ILSAC API specifications to be sold as SM or CJ-4, so this may be an alternative. Classic car oils with elevated levels of ZDDP/ZDTP are also being offered by many suppliers. Regardless, if you are purchasing off-the-shelf oil for your classic car, ILSAC multi-viscosity oils rated SM or CJ-4 should have stated zinc and phosphorus additive supplements for use in older engines or an additional separate additive should be purchased and used with the new oil. As the new API rating SN becomes available in the next year, even more caution should be taken as the levels will be reduced even further.


Jim King

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Current: SE5 (8Ball), TI SS1 (snotty), 1600 SS1 (G97), 1600 SS1 (C686CCR), 2.5TD SE5a (diesel 5a), 6 x random other SS1s.
Previous: SE5, 3 x SE5a, 2 x SE6a, 3 x SE6b, GTC, 2.9i GTC, 3 x 1600 SS1, 1300 SS1, Mk1 Ti Sabre, Mk1.5 CVH Sabre
Chief mechanic for: 1400 K series SS1 (Megan3), 1400 CVH EFi SS1 (Grawpy), 1300 SS1 (Number One) & Sarah's coupe.
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Post by Dennis Nicholas » Mon Jun 17, 2019 10:33 pm

I have been using SYNIONIC AFMT (Anti Friction Metal Treatment) for many thousands miles in the GTC. It started in USA as PROLONG and proved to the American standards people that it does what they claim (I have a copy of the lab reports). It is added to the oil of your choice (10% first oil change then 5% all following changes......also gearbox, axle and power stearing fluid. It is a long chain oil compound and (it would seem like the ZDDP/ZDTP) is ionically attracted to metal so stays put once on. It has a film strength of 22,000 psi compared with even the best of synthetic oils at a fraction of that...a few hundred psi. Good in heat.....as in a turbocharger and does not break down to form any nasties like ordinary oils.
I used to be using molyslip and getting more MPG due to less friction, then changed to AFMT and within the 200 - 300 mile period I was getting even better consumption due to the superior friction reduction. The 10% dose paid for itself within a few hundred miles and from then on all savings are profit...even more with the 5%.....and that is without taking into account the saving in wear of all metal parts due to lack of friction and the superior film strength.
Lab tests by SINTEF and also by MIRA.....both totally independent. I have a copy of the SINTEF lab report I can email. Ditty about MIRA attached.
Sintef MIRA addendum.jpg
Sintef MIRA addendum.jpg (254.04 KiB) Viewed 1457 times
I have an arrangement with the supplier for bulk buying at a good club discount so less than what you see on their website...last order for the Devon noggin people was £300+. The more ordered the cheaper it becomes and delivery is to address you specify, then distribute amongst that area.
5 litre can popular but also in 2litre containers. Also grease with ready added AFMT...just right for the trunnions.
I have no connection to the firm other than being a very satisfied user. Just want people to enjoy the great benefits.....I make no money from arranging the purchase/distribution ......just enjoy the discount price. It can be used in modern cars.....I use it in my petrol Skoda YETI 1.2 turbo petrol (gone from 36 -39 mpg to 41 - 47 mpg) ( No magic just a cleaver bit of chemical technology) It will not cure a rough mechanical but would delay demise.
Contact me if interested.

Dennis


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Post by Old and Slow » Wed Jun 19, 2019 2:22 pm

Hi Dennis,
Presumably the MIRA "Weight Loss" figures relate to loss of metal due to wear? If so, over how many samples of components and also how many hours of operation?
Given the second set of data refers to standard deviation then a sample size of 30 is the minimum, I think, for the Central Limit Theorem to apply.

(Lies, damn lies, and statistics :twisted: )


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Post by scimjim » Wed Jun 19, 2019 3:19 pm

And importantly, what’s the spec of the test base oil from 25 years ago?


Jim King

SECURE DRY STORAGE FOR YOUR SCIMITAR

Current: SE5 (8Ball), TI SS1 (snotty), 1600 SS1 (G97), 1600 SS1 (C686CCR), 2.5TD SE5a (diesel 5a), 6 x random other SS1s.
Previous: SE5, 3 x SE5a, 2 x SE6a, 3 x SE6b, GTC, 2.9i GTC, 3 x 1600 SS1, 1300 SS1, Mk1 Ti Sabre, Mk1.5 CVH Sabre
Chief mechanic for: 1400 K series SS1 (Megan3), 1400 CVH EFi SS1 (Grawpy), 1300 SS1 (Number One) & Sarah's coupe.
CURE THE FAULT - NOT THE SYMPTOMS

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Dennis Nicholas
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Post by Dennis Nicholas » Sun Jun 23, 2019 9:18 am

Old and Slow wrote:
Wed Jun 19, 2019 2:22 pm
Hi Dennis,
Presumably the MIRA "Weight Loss" figures relate to loss of metal due to wear? If so, over how many samples of components and also how many hours of operation?
Given the second set of data refers to standard deviation then a sample size of 30 is the minimum, I think, for the Central Limit Theorem to apply.

(Lies, damn lies, and statistics :twisted: )
Old and Slow wrote:
Wed Jun 19, 2019 2:22 pm
Hi Dennis,
Presumably the MIRA "Weight Loss" figures relate to loss of metal due to wear? If so, over how many samples of components and also how many hours of operation?
Given the second set of data refers to standard deviation then a sample size of 30 is the minimum, I think, for the Central Limit Theorem to apply.
Hi away from home at moment so lack of internet.

Ref MIRA figures I do not have the lab details of their particular experiment but do believe that their independent standing and reputation can't be called into question?

I have a copy of the SINTEF lab report and ditto their reputation. If you would like a copy of the SINTEF let me know your email and I will attach a copy.

As said also, from my own use of the product, I have found it does what both lab reports say in reducing friction.

Dennis


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Post by Old and Slow » Wed Jun 26, 2019 2:55 pm

Just for the record:
I contacted MIRA and sadly their archive only goes back 20 years, so can't provide definitive answers to any of our queries.
Dennis - are you now stocking the additive and making it available to members?


Philip Needham
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Post by Dennis Nicholas » Wed Jun 26, 2019 11:49 pm

Old and Slow wrote:
Wed Jun 26, 2019 2:55 pm
Just for the record:
I contacted MIRA and sadly their archive only goes back 20 years, so can't provide definitive answers to any of our queries.
Dennis - are you now stocking the additive and making it available to members?
Ref stocking it - NO. I just order when there are enough people wanting it to make a worthwhile bulk order. I am just an ordinary retired old crock RSSOC member. The only benefit I get is, like everyone else, from the even cheaper bulk prices than when I first used it and bought it at nearly full price in the smaller quantities. I also believe it keeps the discount price as low as possible by making bigger orders all in one go rather than lots of little orders dribbling in to them which would make them less keen to give us the club discount. Hence the "get up a local group of people wanting it and it will be all sent to one address for local distribution" I like discounts, especially on stuff like this, which ultimately saves you money even at full price and preserves the mechanical bits and like to pass on info that is helpful to others.

Dennis


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Post by Old and Slow » Thu Jun 27, 2019 8:12 pm

Dennis Nicholas wrote:
Wed Jun 26, 2019 11:49 pm
an ordinary retired old crock RSSOC member
Same as me then!! :(

Basic questions - what quantity is needed for each oil change? I have two old cars so double the quantity, and assuming I buy enough for 3 years, that's six lots.
How do you raise sufficient interest to make a bulk purchase, but then there's the delivery issue; do they deliver direct, or would we need to visit sunny Devon to collect?
Philip


Philip Needham
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