Hi guys. I need some help.. I would realyl like to know th ediffrence between a XXW-30 synthetic oil and a XXW-50 synthetic oil. As far as i have looked, the XXW-50 seems to have a better flash point and viscosity index. BUT, i would like to know how to actually read these numbers.. for exmaple, i know a 5W-XX is a thinner oil than a 10W-XX, but i dont know what the other number means. I am assuming i am right in thinking it is just flash point numbers or something? someone help my confsed brain. THanks guys, i appreciate your input.

 

Simply and not technically:

The first number with W tells the viscosity for the cold oil and the last number for the hot oil. So small first number is good @ winter and high last number good for hot motor. For example in turbo engines it's good to use something like 20W-60. I use 5W-50 around the year.

 

so for a 5-50, it wont get thinner than 5, and not thicker than 50 when hot? i have been using 5W-50 all year, and our temp ranges from -30C to +30C. think i should stay with this then? i waws debating on going with 10-30 for summer, and 5-30 for winter.

 

why is it bad? as a question, not mocking you. I know for example the chevrolet dealerships put the 50 ni the vettes up here, as well as mercedes. this is why i am confused. Some say bad, some say good. I am tryignt o get facts and not opinions.... by the way, im sure it matters that i am in a much stupider climate than yourself... my temp range is freaking dum.

 

Running 50-weight oil is a bad idea because the clearances in Mazda engines are designed for thinner 30-wt oil. The engine's oil pump has to do more work to push thicker oil through our engines' tight clearances, and running an oil that is too thick will raise oil temperatures, make the pump work too hard and hurt lubrication for no good reason. The only good reason to run 50-wt in a Protege is if the engine has very high mileage and is suffering from low oil pressure due to excess bearing clearance.

BTW running a 50-wt oil in weather as cold as Edmonton is a REALLY bad idea. You don't need 50-wt oil in a Protege in Texas when it's 105 degrees F outside. I would stick with the manufacturer's recommendations: 10W-30 for hot weather, 5W-30 for cold.

 

allrighty.. thanks for the info.

 

Here is what you should do ZIO....get your manual....look in it...there is a section that descusses the oil you need to use for your engine based on the MIN and MAX temps in your climate....it will tell you which grade is best suited for your area....go with it.

 

agree completly!!!!!!! I would just use synthedic, thats the only thing i want to say

 

some people do not know why synthetic is better from organic oil. Why don't you post your reasoning.

Some one said that the vettes come with a XXW-50 where they live. All new corvettes come with 5W-30 Mobil 1 in their oil pan. I doubt the dealership changes all the corvette's oil when they get 'em. Unless you live in an extreme climate that would not be cost prohibitive.

 

i am telling you what they do here, so if you dont agree, then i dont care. i asked a question, i had helpful people give some info, so lets just end it here.

thank you.

 

I run 15W-50 mobile one pure sythetic in my trubo protege MP3 per the kit manufacturers reccomendations.

 

synthedic oil has smaller molecules so it fits in the little inferfections of the motor easier than organic oil. Turbos have to run that higherweight i guess for the temp of the motor and for the turbo itself.

 

Hey ZiO! Nice Avatar! And I'm assuming the first line in your sig is to quote "Chunk" right? LOL!

A classic movie indeed...