- May 5, 2012
Well I recently changed the oil in the 420a. I had 5-30 advanced auto generic oil in it because I was short on cash. Needless to say I put in 5-30 full synthetic pennzoil. I feel an unbelievable difference in the amount of throttle response, power and gas mileage. Also it's much more quiet. Not that it knocked or anything before hand but it just sounds like it running so much better. My question is could oil really help that much or is it in my head? If I change my gear oil to royal purple will the transmission feel better? Any comments or input would be greatly appreciated.