I recently changed my oil.from 5w 30 to 20w 50. I drive a lexus gs 300 2004 model. When I buy the car,its mileage was 220k. Now its on 300k miles.

I noticed my mobil 1 5w 30 dries up quickly,saw some oil spillage on top of water pump and oil ,but have not had time for mechanic. So I topped with 1 liter of 20w 50 since mobil had ran out of the semi synthetic 5w 30. However I noticed that my gas mileage had increased . Is there any risk on using this.


Shockingly the oil is still guaged,compared to the 5w 30. A mechanic told mee ,that the engine is an iron engine and can take any form of abuse. Now onsiidering how hot nigeria is ,most times its between 88 to 100 degrees during day time.. can I continue using it.