For instance, why is a heavier oil used on a turbo honda versus the factory recommendation 5w30 (b series). Im not opposed to using it, just want to know the reasoning. I always learned that using a heavier oil on a car can ruin internal componenents (years ago).

At the same time, using a lighter oil in a car is used for racing application only. When I hear "racing application" I think of maximized performance however short lived.

 

after a couple years of experimenting with oil weights....(i can afford to experiment with a SOHC), i've came to a few conclusions, as far as Turbo engines are concerned.

-with a 1/2 dead, but still very useable turbo, slightly heavier oil, when hot, means less oil lost out the exhaust from turbo-puke.

-my old d16a6, that ran awesome, and still would, (if dropped back in) before my build a few months ago, LOVED extended sessions on a roadcourse with heavier oil (10w40 sythetic). it ran 100%, didnt loose much at all, didnt blow much out the breather into catch can..

-prior to running 10w40 synthetic, i was running 5w30 synthetic. i lost about twice the oil out the turbo, and a lot more out the breather. the engine ran fine on it though. no differences there. thats all i can contribute.

 

burns less? when motor undre alot of work

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by itr1244 &raquo;</TD></TR><TR><TD CLASS="quote">burns less? when motor undre alot of work</TD></TR></TABLE>
yah the viscosity is usually better in a thicker oil versus a thinner oil of the same brand/make

 

The heat produced by the turbo will surely cause the oil to shear/thin to a lower weight. Therefore, using a heavier weight oil would be beneficial for an engine equipped w/ turbo. The turbo'ed engine's oil would most likely need to be changed more often than a N/A engine's oil would.

 

fwiw, i've used mobil 1 full synthetic 5w30 since my first oil change on my itr since i purchased it brand new.

I recently changed to castrol germany full synthetic 0w30 at .RJ's recommendation.

I have also been using both of the above brands on my turbo itr as well.

So I guess I am going against the grain in using a "thinner" oil, however the oil testing that I've seen for what I'm using is better than even those thicker oils advertised protection.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Black R &raquo;</TD></TR><TR><TD CLASS="quote">fwiw, i've used mobil 1 full synthetic 5w30 since my first oil change on my itr since i purchased it brand new.

I recently changed to castrol germany full synthetic 0w30 at .RJ's recommendation.

I have also been using both of the above brands on my turbo itr as well.

So I guess I am going against the grain in using a "thinner" oil, however the oil testing that I've seen for what I'm using is better than even those thicker oils advertised protection. </TD></TR></TABLE>

Also note that the rating on that 0w30 german syntec is very very similar to a normal rating of 10w40.... So your "thinner" oil... really isn't that thin.

 

I use 5w30 in the winter and 10w30 in the summer.

As far as a turbo application I think it would break the oil down faster therefore requiring a higher weight oil.

 

Thinner oil will break down much much quicker in a turbo car. Esp in summer months.