[2fast4u]

ive been using either
Mobil Clean High Mileage 10w40 / Castrol GTX High Mileage 15w40 or Castrol Multigrade20W50
for the last 4 yrs as my cars done over 450K.

As i had some car issue with regard to engine remaining ON for couple of seconds after turning key OFF see
http://www.team-bhp.com/forum/techni...rning-off.html
I went to the Nissan dealer Service, the dealers mechanic opened the engine oil cover and inspected and recommended to use Nissan SJ 20W50 for the first time I switched brands reluctantly BUT the performance after the change is absolutely amazing.

Earlier the engine was audible now i have to see the rpm meter to know its running. the engine noise has been cut off almost completely.
the cars running fine,
the engine cuts OFF the moment key is switched to OFF
with a light foot it sees 100 and kind of sails quietly.

i am wondering if Castrol & Mobil are getting duplicated / adultereated by middlemen
or
is it just the grade difference that has made the impact
or
is it Nissan Oil which makes the difference this being a Nissan.

[sharathjeppu]

That's pretty interesting to note. Would any of the members here have feedback on performance improvement after just changing the Engine Oil.

Had another question in connection with my car. In the morning (Cold Engine), my swift almost never starts with the first key turn. It is always on the second key turn. This was not so with my Wagon R which used to start on the first turn. Any reason why does this happen?

[Ram]

A film of engine oil on metal surfaces affords lubrication (reduces metal against metal friction) also convects away heat away from hot engine parts. With a detergent in the oil, it also cleans and inhibits corrosion. There are two broad kinds of engine oil: Mineral oil (petroleum based) and Synthetic (read expensive and high performance).

In cold countries, people don't go above 20-weight oil. But even 20-weight is too high for starting an engine in freezing atmospheric temperatures. Then you need 0-weight or 5-weight.

By blending a polymeric viscosity index improver, the oil can behave as 5-weight oil when cold and 20-weight oil when hot. This is called a multigrade 5W20 oil.

In India we don't go above 40-weight. In Bhopal/Nagpur like temperature extremes 10W40 is a good multigrade oil to use.

2fast4u, as ambient temperatures rise, engine operating temperatures rise too.
Assuming you are driving in the hot middle-eastern desert conditions, you need the 50-weight oil to protect your engine from heavy wear.

The more viscous the oil you use, the more silent your engine will run. Of course it will encounter more continuous resistance and be more fuel-inefficient. And higher viscosity oil is not necessarily good for the engine. The oil won't flow through all the engine's oil passages swiftly and properly. While it might quieten the engine, it wont lubricate it properly and long term there will be more wear and tear.

There are commercial friction reducing additives you can use. These are usually a colloid of a very fine, exceptionally slippery substance -- Molybdenum Disulphide, Polytetrafluoroethylene (PTFE)[DuPont's Teflon and the Australian Nulon-E30], ZX1 and Active8 are anti-friction agents. Mfrs claim these agents reduce wear by 'bonding' to the bearing surfaces filling in surface imperfections.

Studying the automotive used-car market in the US in the 1980s, I learned that while selling an old car, there was an unethical practice that cheats would use. They would dump a big bagful of graphite-powder into the engine oil, temporarily increasing its viscosity so that it would run quiet long enough for a buyer to be hoodwinked into buying it.

Ram

[2fast4u]

ram@ so do u suggest i drain it off and switch to mobil high mileage or castrol gtx these are the ones i used the mobil being 10w40 and castrol being 15w40

[Ram]

If you're happy with Nissan SJ 20W50, stay with it.

What's needed and available locally, will depend on where you are.
I don't know whether you're in Pune or Bahrain.

Nissan Fasflo 100% Synthetic Racing Oil 20W50 meets SL and CF specs. It meets the severe lubrication requirements of high temperatures, high rpms and extreme driving conditions in equatorial conditions such as in Singapore.

Is that what you're using?

Ram

[gd1418]

I am sure that the vehicle you own is used in Bahrain and not in Pune. As such the ambient temp in Bahrain is generally on the higher side as generally found in the Gulf area. Hence an oil with a rating of Grade 50 is absolutely fine in those conditions. i know it would sound funny these days to suggest warm-up the first thing in the morning as vehicles are made for instant high performance. But, a 2 minute warm up in the morning at first start won't harm anything..!!!

Originally Posted by 2fast4u

ram@ so do u suggest i drain it off and switch to mobil high mileage or castrol gtx these are the ones i used the mobil being 10w40 and castrol being 15w40

[2fast4u]

yes i am based in bah. and thanks ram gd1418 for ur response. as my driving is not agressive and within speed limits i'll continue with the Nissan Oil and observe.

thanks again.

[gd1418]

With due respects to all experimenters, researchers & users on the BHP forum, I would like to state something. Nobody knows what is good/bad for the vehicle other than the manufacturer/creator himslef. If they reccommend a particular grade of oil, grease or fuel, then rest assured that they must have done immense research on various products available in the market before arriving at that conclusion.

Though I am not averse myself to experimenting, I use a premix of acetone & 2T) in my fuel tank of Safari, I generally prefer to stick to what is suggested in the manual by the company.

Originally Posted by 2fast4u

yes i am based in bah. and thanks ram gd1418 for ur response. as my driving is not agressive and within speed limits i'll continue with the Nissan Oil and observe.

thanks again.

[jkdas]

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