ARTICLE: Synthetic oil vs Mineral oil

[sumeethaldankar]

Originally Posted by sumeethaldankar

I have decided to go for Mobil super xhp 15w 40, i had called up a dealer and when i told him i wanted it for a 800 he was suprised and said 15w 40 is only for diesel engines and for the 800 i can use 20w 50 but Mobil's web site (Mobil Super XHP 10W-40, 15W-40 and 20W-50) say's it's for gasoline as well as diesel.some clarification on the same could help.

thanks

Changed to Mobil 10W 30 as super xhp was not available.The engine feels a little crisp and has become a tad fun to drive. The can had a Approved by maruti stamp on it but i can't find much details about this particular oil on the net.

[Gansan]

@Sumeet

10w30 for an M800 is not advisable. When the mfr recommendation is 20w40, you can use 15w40/10w40/even 0w40. The lower number can be = / < recommendation but the upper one should always be = / >.

[sumeethaldankar]

Originally Posted by Gansan

@Sumeet

10w30 for an M800 is not advisable. When the mfr recommendation is 20w40, you can use 15w40/10w40/even 0w40. The lower number can be = / < recommendation but the upper one should always be = / >.

That's great now more trouble for my car.Had itscraped up against a bus last week and this week i get to know i put in the wrong kind of oil.What kind of damage can i expect with this oil.It's really running smooth and crispy.I drive pretty low in mileage figures atleast i could keept it for 3 months or so ?

[Gansan]

40 is the viscosity number (thickness) the oil should maintain when the engine attains normal operating temperature. A 30 oil will maintain a thinner film. Not advisable in Indian summers. If the climate is cool in your place at present, I suppose you can keep it for the time being. But if I were you I will change it asap. And don't worry, nothing much would have happened in such a short period. Please use your discretion.

Having said that, the oil recommended for my Splendor is 20w40, but the Hero Honda A.S.S guys use the HH 4T+ oil, which is a 10w30 oil. The bike has been on this diet for more than 9 years now. But then that is the oil currently endorsed by the manufacturer at their authorized workshops,so I don't bother.

[sumeethaldankar]

Originally Posted by Gansan

40 is the viscosity number (thickness) the oil should maintain when the engine attains normal operating temperature. A 30 oil will maintain a thinner film. Not advisable in Indian summers. If the climate is cool in your place at present, I suppose you can keep it for the time being. But if I were you I will change it asap. And don't worry, nothing much would have happened in such a short period. Please use your discretion.

Having said that, the oil recommended for my Splendor is 20w40, but the Hero Honda A.S.S guys use the HH 4T+ oil, which is a 10w30 oil. The bike has been on this diet for more than 9 years now. But then that is the oil currently endorsed by the manufacturer at their authorized workshops,so I don't bother.

Well actually the Mobil Can said it's recommended by Maruti and came in a 3 L qty.Also i remember before i had used Mak supreme for almost a year and i think it was 10W 30.Car ran fine except it was a bit noisy.

[sgiitk]

I would be hesitant to use a SAE30 oil in a older Maruti engine. The oils recommended are all SAE40 or 50. The newer K series engines apparently are quite happy with SAE30 oils.

[saildrive]

My oil change is due...got a Indica Xeta 1.4 GLS (petrol); will canyone know which Synthetic Oil I should put as am looking to change the same at one of the garages since the dealer will end up charging taxes etc..

This way will buy the oil from a shop and avoid taxes.

[Gansan]

Originally Posted by sumeethaldankar

Well actually the Mobil Can said it's recommended by Maruti and came in a 3 L qty.Also i remember before i had used Mak supreme for almost a year and i think it was 10W 30.Car ran fine except it was a bit noisy.

Well, if you see the oil selection chart given in your owner's manual, it will indicate the SAE grade to be selected according to min - max temperature range prevailing in the area one lives in. It will include 10W30 grade also, but that kind of climate can be found only in hill stations or at best during winter in some locations. Hence the recommended grade for all older generation Maruti engines is 20W40 or 20W50 only on a round the year basis.

The recommended grade for the K series engines is synthetic 10W30 and that is what you would have seen on the Mobil can. They use it in the MASS also.

[nitrous]

Originally Posted by sgiitk

I would be hesitant to use a SAE30 oil in a older Maruti engine. The oils recommended are all SAE40 or 50. The newer K series engines apparently are quite happy with SAE30 oils.

SAExx are mono grade oils and it would be wrong to use the term 'SAE' with multigrade oils.

Modern engines are engineered to run on lighter oil like xW30 for better fuel efficiency.
They compensate the reduced lubrication from the lubricant by friction reduction techniques such as plateau honing, etc.

[AstonMartin]

Completed the one year/10,000 KM service for the Maruti Alto last day. SA advised using Shell Helix Ultra and said the next change would be needed only after two years. I let him fill that and the bill was around 2750. I don't feel any difference with the engine performance. Those guys pasted a Shell Helix sticker on the windshield !!

[Raccoon]

Originally Posted by nitrous

SAExx are mono grade oils and it would be wrong to use the term 'SAE' with multigrade oils.

Modern engines are engineered to run on lighter oil like xW30 for better fuel efficiency.
They compensate the reduced lubrication from the lubricant by friction reduction techniques such as plateau honing, etc.

Hope you mean to say that using the term "SAE x" would be wrong when talking about a multigrade oil. The term "SAE xWy" would be quite correct when defining a multigrade.

[sgiitk]

Originally Posted by nitrous

SAExx are mono grade oils and it would be wrong to use the term 'SAE' with multigrade oils.

Modern engines are engineered to run on lighter oil like xW30 for better fuel efficiency.

Please do not forget in the current context if an oil is aWb then only b is of relevance. At speed, when the engine is hot b decides whether you risk rubbing metal on metal. I was writing purely in this context.

What is a. It is the viscosity index of the cold oil, and decides the rate at which it spreads into the engine when you start. Too low and you may risk oil loss from the seals. Also, with hydraulic tappets it also determines how fast so they come up to proper behaviour. W stands for Winter Grade.

If you cannot get the oil specified then you can go lower in a but not in b.

What is aWb.It is an a grade a oil with viscosity improvers which prevent it from going thinner than monograde b when hot.

@AstonMartin: oil change in two years - does bug me a bit. Maybe the experts can opine on this one.

[AstonMartin]

Originally Posted by Gansan

I am using the Shell Helix HX5 and am very happy with it. It is a mineral 15w/40 API SL oil. Costs Rs 915 (MRP) for 4 litres. Since my usage is only ~ 5000 KM per year, I use this oil and change it once in 6 months, even though it is good enough for 10,000 KM/ one year. Try it, it is more than enough.

@Gansan, Aren't you using a completely wrong oil for your car. See the attachment.

[devarshi84]

Isnt it better if the range of temp for synth oil is less? For eg wont 15w40 be better than 0w40 if my car engine doesnt reach those extreme temperatures?

[Gansan]

Originally Posted by AstonMartin

Completed the one year/10,000 KM service for the Maruti Alto last day. SA advised using Shell Helix Ultra and said the next change would be needed only after two years. I let him fill that and the bill was around 2750. I don't feel any difference with the engine performance. Those guys pasted a Shell Helix sticker on the windshield !!

Originally Posted by AstonMartin

@Gansan, Aren't you using a completely wrong oil for your car. See the attachment.

This document does not seem to be from their Indian site. The HX7, a semi synth IMO, is not available here. The HX5 is their best all round mineral based oil for all petrol engines and they promote it as such. This oil is API SL grade and is the next best oil after Ultra for new, but older gen, cars. For much older engines with a lot of KM on the clock, the HX3 (red can) may be more suited.

So I am indeed using the perfect oil, much superior to the MGO (20w40,API SF) for my Alto. Just ponder : At Rs 915.00 for a 4 litre can, I can change the oil every six months and still save > Rs 1000 when compared to the price of Ultra! Moreover as my car is still < 7000 KM, I can't switch to Ultra even if I wanted to. My car does only ~3K KM in six months.

As you have crossed 10K KM, it is ok to fill Ultra. But it should still be changed once every 15K KM / one year, whichever is earlier. Don't you believe what the MASS fellow says, it is not correct!