Just curious,is any one using Synthetic or conventional 5W-20 oil in your RX??

 

You shouldn't have problem running 5w-20 vs 5w-30. 5w-20 is meant for better fuel consumption. It is better you use the type manuf. recommended. For first gen of RX, the car must be old, so it is not worth to run thinner oil.

 

yeah thats kind of on the same line as I`m thinking.I have however seriously contemplated trying the Valvoline full Synthetic racing oil VR 10W-30 It might be a good combination for this engine.

 

I am using synthetic Mobile 1 oil. I think it was 5w-30 high performance.

 

My new Corolla calls for 5-20. I think across the board other manuf. have gone to 20 wt. oil. Better fuel economy. I am thinking that the Mobil 1 5-20 may have less sludging issues and maybe that`s why they went thinner?

 

I noticed this to with the 5w-20, it "supposed" to give better mpgs, but as I have been shown and researching it isn't by much. But these days, I would take that little just to save on gas.