Saturday, December 26, 2009

Can I use different motor oil different grade other than the one suggested by the car manufacturer?

i own a 1000cc compact car..... the car manufacturer suggested castrol 10W-30 grade motor oil. on the next servicing, i plan to use better brand which is Shell Helix Ultra Fully Synthetic grade 5W-40. Will my car engine get damaged if i use different grade other than the suggested one? Thanks.Can I use different motor oil different grade other than the one suggested by the car manufacturer?
5W30 versus 10W30


Virtually all new passenger vehicles sold in the U.S. use either 5W30 or 10W30 oil. The difference between the two is that the 5W30 flows better when cold, so if you live in a cold climate or operate your vehicle in a cold climate during the winter months, you should use 5W30 if it is the preferred oil for your vehicle. If you live in a sub-tropical climate and don't operate your vehicle in cold climates, then 10W30 is acceptable as long as the manufacturer specifies that it is permissible to use it.





Is there a disadvantage to using an oil that flows better when cold, i.e. 5W30 versus 10W30?


Sometimes, but usually not. The crux of the issue is this: the bigger the difference between the cold oil viscosity and the hot oil viscosity, the more the volume of viscosity modifiers and the less the volume of base stock. If you are good about following the manufacturer's recommended oil change interval then stick with the 5W30 if that is the preferred oil for your vehicle, even if 10W30 is acceptable in warmer climates. Older cars may specify 10W30 only. This is because they need a little more viscosity when cold to keep a protective film on the cylinder walls. There have been instances where the larger amount of viscosity modifiers that are present in 5W30 have broken down due to excessive heat and have left carbon deposits on the valves, but this is extremely rare. The proper fix would be to reduce the excessive heat, but the workaround was to use an oil with less viscosity modifiers.





Synthetic oil was originally developed for high performance racing engines. Mobil tried to popularize synthetic oil for passenger vehicles back in the early 1970's. At the time, Mobil was promoting 20K or 25K oil changes with synthetic, but they soon backed down from this. Synthetic oil is a good choice if you have a vehicle with a high performance engine (in fact synthetic is required for many of these engines). It is also a good choice if your vehicle is operated in extremely cold climates. It has higher resistance to breakdown caused by heat and it flows better in extreme cold. Unfortunately for the synthetic oil industry there is virtually no advantage to using synthetic oil in a non-high performance engine that is operated in moderate climates. You probably could go a bit longer between oil changes with a synthetic, i.e. following the normal service schedule even if you fall into the severe service category, but I wouldn't advise this. In short, synthetic may give you the peace of mind of knowing that you are using an oil that is far better than necessary for your vehicle, but it won't reduce wear or extend the life of the engine. The mistake some people make it to wrongly extrapolate these benefits onto normal engines operated in mild climates, with the ultimate lack of any knowledge being manifested with statements such as ';synthetics provide 'Peace of Mind,' or 'Cheap Insurance,''; or other such nonsense.





Never use a non-API certified synthetic oil (there are many of these on the market). The problem with the non-API certified synthetics is that they contain too much phosphorus (in the form of the additive ZDDP (Zinc Dialkyl Dithiophosphates)). The API has limited the amount of phosphorus because phosphorus shortens the life of the catalytic converter. These oils are fine for snowmobiles, motorcycles, and older cars that don't have a catalytic converter, and the extra ZDDP does provide additional wear protection. Unfortunately, the marketers of some the non-certified oils do not explicitly and honestly state the reason for the lack of API certification. You can check the status of API certification on the API web site. Be certain to go not just by the manufacturer name but by the actual product as well. This is because a manufacturer will sometimes have both certified and non-certified products. Suffice it to say that Mobil 1, Royal Purple, Castrol, %26amp; Havoline all make synthetic oils that are API certified and that can be purchased at auto parts stores and other retail outlets. Amsoil has one product line, XL-7500 that is API certified, but it's other lines contain too much ZDDP to be certified and should not be used in vehicles with catalytic converters.Can I use different motor oil different grade other than the one suggested by the car manufacturer?
Nope, no damage. I don't see any advantage in synthetic at all. I buy any oil company oil on sale: Sunoco, Mobil, Shell, anything but stay away from independent or store brands or junk like STP or Cam 3 or the like.
I myself run Valvoline's 20-50 in my v8's when I'm in the southern states like Florida, but up here in the cold I run 10w-30 in the winter and 15-40 for the warmer months. I have found no difference in wear between the oils. As far as synthetic I wouldn't recommend it unless the vehicle recommends it or has low miles (10000) then you shouldn't have any issue's...
If you switch to synthetic there's a good chance your engine will start to leak / seep oil.

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