[sgiitk]

Just advised a CA friend of mine to switch his City ZX from oil change every six months, to an annual change making sure that the oil is API-SL or better. He does barely 6000 km per annum. Synth- semi- or mineral is irrelevant.

[i74js]

Turbo Charges of Diesel / Petrol motors tend to undergo more wear and tear due to poor oil quality / use of mineral oil.

Can people in the forum share their experiance on the impact of performance of Turbo Chargers with use of synthetic oils? Do they perform better, will there by less carbon deposits? Any other advantages?

[Sawyer]

Recently read somewhere - for multigrade oils, the spread in the grades should be less than 30, any more and it is difficult for the oil companies to get it to perform in extended use. As an illustration, a 5w-30 oil is better than a 10w-40. Regardless of the mineral v synthetic thing.

[swarnava.m]

Originally Posted by Sawyer

Recently read somewhere - for multigrade oils, the spread in the grades should be less than 30, any more and it is difficult for the oil companies to get it to perform in extended use. As an illustration, a 5w-30 oil is better than a 10w-40. Regardless of the mineral v synthetic thing.

That comes as a bit of a surprise and could be a cause of concern for many. Any source of this information?

[Sawyer]

Originally Posted by swarnava.m

Any source of this information?

Here is one, there are more:
http://www.upmpg.com/tech_articles/motoroil_viscosity/

[Su-47]

Originally Posted by sgiitk

Just advised a CA friend of mine to switch his City ZX from oil change every six months, to an annual change making sure that the oil is API-SL or better. He does barely 6000 km per annum. Synth- semi- or mineral is irrelevant.

Mine is a similar case: About 6k-7k Kms/year on a Ritz-Petrol. IIRC, the manual mandates an oil change once a year or 5k. If synthetic oil does make the car smoother, I can give it a try. Any recommendations on brand and expected pricing etc.?

Thanks,
Su-47

[Gansan]

Originally Posted by FlatOut

A friend of mine advised against most semi-synthetics, which he suggested were best avoided. He advised that a straight mineral oil of good quality was a far better choice. Reason? - semi-synthetics were cheap mineral oils with a synthetic additive package and the big profit-earners

On the other hand, fully-synthetic oil were the dogs b%ll%cks. Provided they were the right viscosity and used in suitable engines.

Who was/is he? A chemist employed by an oil giant in the lubricant 'department'.

Is that so? I have been regularly using Shell Helix HX-5, which is a mineral 15W40, API-SL oil. Recently switched over to HX-7 at a marginally higher price. This one is "synthetic technology", I suppose another jargon for semi synthetic. But this oil is 10W40, API-SM. How come?

I bet they will not use any "inferior" mineral oil but just the same base oil they use for their HX3 and HX5 range.

[Sawyer]

For all normal - i.e not racing/rallying - use, a good, not counterfeit, mineral oil of the latest API spec - SM/SN now - is all that is needed. Changed as recommended by the manufacturer of the car. SL is also good enough, to be honest.
All talk about smoothness on using expensive fully synthetic oil is either expectation bias founded or the outcome of a proper service of any car which is when the oil changes are usually carried out. All cars are a smoother drive after a good service.

[FlatOut]

Originally Posted by Gansan

Is that so? I have been regularly using Shell Helix HX-5, which is a mineral 15W40, API-SL oil. Recently switched over to HX-7 at a marginally higher price. This one is "synthetic technology", I suppose another jargon for semi synthetic. But this oil is 10W40, API-SM. How come?

I bet they will not use any "inferior" mineral oil but just the same base oil they use for their HX3 and HX5 range.

Like any statistic, any test, the API test is a result at the point of testing and does not necessarily reflect the real world. Many people have bought a new car on the basis of very authorititive-sounding EU economy figures only to be bitterly disappointed. I wonder how many run a straight mineral oil for 6000 miles then have it tested, then do the same for a semi-synthetic? I think the answer will be very close to zero. If you know of some results then I really would love to know, Gansan.

I'm not a betting man, but I think you may be wrong on this. My money is very hard earned, I can also rebuild my own engines - I choose NOT to use semi-synthetic oils. Were I a betting man, instead of an engineer, I may take more notice of the propoganda/numbers on the product labels.

[Sawyer]

Originally Posted by Gansan

Is that so? I have been regularly using Shell Helix HX-5, which is a mineral 15W40, API-SL oil. Recently switched over to HX-7 at a marginally higher price. This one is "synthetic technology", I suppose another jargon for semi synthetic. But this oil is 10W40, API-SM. How come?

I bet they will not use any "inferior" mineral oil but just the same base oil they use for their HX3 and HX5 range.

The grade move needs a change in the base oil, not just in the subsequent additive package or manufacturing technology.
Consider this: it is more expensive to keep two API grades in the line up than it is to standardise on one grade, even if that is the more advanced one. But, in transition and unless others have done so too, there is the marketing opportunity to extract a higher price for the better oil, so how do you do this? The market at large doesn't understand the alphanumeric jumble of letters as a differentiator, but "synthetic technology" as a blurb is noticed even in rural markets not fully conversant with English. But it doesn't mean a thing in itself.
Semi-synth is even cleverer. A long time ago, a liquor industry insider told me that if he added a peg of Scotch to a barrel - or more - of Indian whisky, he was legally entitled to call it " Blended with Scotch", and sell it at a higher price for that attribute. I am sure you can see the analogy!
Pure synthetic is a different story, but a same API grade mineral is just as good for normal road use cars.

[Gansan]

Originally Posted by Sawyer

Pure synthetic is a different story, but a same API grade mineral is just as good for normal road use cars.

I am aware of the Scotch blending analogy, yes!

But coming back to engine oils, I don't see a same API grade in mineral. They seem to stop at API SL,same as the Helix HX 5 I was using. Semi-synths are rated as API SM. And full synthetics as API SN. Seems to be true of all brands.

But interestingly the same semi synthetic oil sold as AX7 which I buy for my bike, is rated as API SL.

But do you really think Shell would have used an inferior base oil for this range? Will I be better off switching back to the regular mineral oil asap?

[Sawyer]

Originally Posted by Gansan

But coming back to engine oils, I don't see a same API grade in mineral.

But do you really think Shell would have used an inferior base oil for this range? Will I be better off switching back to the regular mineral oil asap?

Castrol Magnatec is mineral - and in SM/SN grades.

No well known oil company will knowingly sell a product that will hurt your engine, as long as you use oil with the right grade/viscosity, and change as recommended by the car maker. So, no, no need to switch back asap - my advice was only from a view of economy - that there is no need to pay the extra money for the fancy names. But if you have the money to spare, and it results in a feel-good thing, go ahead.

[Sawyer]

By my reckoning, oil related engine damage in the overwhelming cases in India would be caused by one or a combination of:
1. Unwitting use of spurious oil
2. Not keeping track of the oil level
3. Not changing the oil as required/recommended by the engine maker
As long as you take care of these factors, the engine will be fine.

PS: When I took my new petrol Toyota for service, I was pleasantly surprised. Toyota sells both mineral and synthetic oils, and the service advisor said to me, it is your choice, both are fine.

[Dr.PK]

Dear fellow BHPians, I need some advice. I have a 2003 model wagon r mpfi (fd10, I presume) which has largely run on CNG and has clocked 107000 kms till date. it has always been serviced at maruti service masters (owned fully by maruti Suzuki) only. now I am planning to go to for its service at a trusted neighbourhood garage. may I ask a few questions as under:
1. the folks at maruti have used shell 5w30 as per the last service record. as far as my meagre knowledge goes, it should have been 20w40. service manual does not state any thing. am I correct?
2. Is it possible to use synthetic oil in my car at this mileage? I do intend to keep the car as it is functioning properly.
3. If yes, any recommendations from fellow BHPians? Total and Mobil 1 appear to be good from what I gather from the posts.
4. any special considerations on engine oil? assuming that the car is largely driven on CNG, and rarely on petrol.
any help would be deeply appreciated. Thanks

[Gansan]

Originally Posted by Sawyer

But if you have the money to spare, and it results in a feel-good thing, go ahead.

No, thanks!

All Maruti A.S.S.places are now using only semi synthetic 5W30 MGO for all cars, whereas that is recommended only for the K10 engines. Previous engines needed 20W40.

Compared to that, the 10W40 HX 7 is much better, so I will keep it!