Oils And Numbers

[12DrinkMore]

I am using 20W-50 motorcycle oil from Tesco. Along the same shelves there are a whole bunch of oils for diesels, turbo-diesels with a bunch of different numbers. I understand (maybe incorrectly) that synthetic oils are more "slippery" than the petroleum based products and have a longer life. They are also much more expensive.

If I started using a 20W-50 oil specified for diesel engines in my bike, is this going to be a major problem? From the number the viscosity is exactly the same 20W referring to the lower temperature viscosity and 50 the upper temperature viscosity of this multi grade oil.

I'm totally ignorant on this subject so maybe somebody can help?

[neverdie]

I am no expert on this but have taken interest in oils in the past.

Whenever most people think about engine oil they think about lubrication, which is fair enough, but lubrication is not the only thing engine oil is used for. Its also used for cooling. As you are probably aware, Diesel engines operate at a higher temprature than your typical petrol combustion engine. I am led to believe that this is one of the reasons that different oils are offered between Diesel and Petrol. I can't offer a full explanation of it all but I was once told that Diesel oil won't cool the petrol engine as efficively as oils designed specifically for petrol engines.

I was also told that Diesel engine oils, as compared to petrol oils, do not have very good low temperature sludge formation resistance, if that means something to you. I think that the diesel engine oils are usable in a petrol engine but if there are problems associated with sludge formation resistance, then you would be very wise to change to the correct oil.

I never could quite understand why someone would want to take unnecessary risks with engines worth thousands of dollars for the sake of a few dollars of oil.

I am sure a mechanic, legally trained mechanic is about to shoot me down in flames, but hopefully this helps.

One other thing, diesel oils contain properties or cleaning agents to help control soot, I don't think they will hurt your petrol engine but they may not help it either.

Edited December 19, 2008 by neverdie

[Zzinged]

12Drink, what motorbike are you using it with?

[12DrinkMore]

12Drink, what motorbike are you using it with?

I am using the Castrol 20W-50 motorcycle oil (bought from Tesco) in a Honda Dream and a Kawasaki Ninja.

I haven't seriously considered putting the diesel lubricant in them, there is little or no price advantage, but was interested in the difference in the various oils.

[Zzinged]

One major difference, especially for bikes that have wet clutches, is that some vehicle oils have anti-friction components in them. If you use one of those oils on your bike with a wet clutch... it won't be very happy

Also, like Neverdie said, diesel oil is supposed to have more chemicals to keep soot under control.

As for synthetic oil, they have larger operating temperature ranges. Synthetic oils will freeze at lower temps than conventional oils, and break down at higher temps than conventional oil. Basically, it's better than petroleum based oils because it's more efficient and operates at all sorts of temperatures. However, fully synthetic oils apparently don't keep the engine clean as well as mineral oils. Then there's always semi-synthetic for the best of both worlds... hehe

Edited December 19, 2008 by Zzinged

[Richard-BKK]

Hi 12Drinkmore,

I not want to be rude, it is almost the holidays and I had a really funny party, but you want us to really answer about motor oils you can buy at Tesco? I can remember that I looked at the car selection of Tesco-Lotus Suksawat, as I can remember it correct it was all branded Tesco brand.

I have in my live only one rule if it comes to engines, never hold back on good oil, you can buy a few cheap shoes for a season but never hold back on what a engine needs... try to hold some dignity in qualify ...

[12DrinkMore]

Hi 12Drinkmore,

I not want to be rude, it is almost the holidays and I had a really funny party, but you want us to really answer about motor oils you can buy at Tesco? I can remember that I looked at the car selection of Tesco-Lotus Suksawat, as I can remember it correct it was all branded Tesco brand.

I have in my live only one rule if it comes to engines, never hold back on good oil, you can buy a few cheap shoes for a season but never hold back on what a engine needs... try to hold some dignity in qualify ...

Hi

I am using branded Castrol 20W-50, however I am sure that Tesco does not have its own refinery, and will be buying "own brand" from some major manufacturer. The question was more about oils in general, for example what is the difference between an oil 20W-50 sold as suitable for diesel engines rather than a similar spec oil sold for petrol engines?