Any general thoughts, pro or con, on using 20-50 in my 86 190E 2.3, 8 vavle or 86 300E? The Denver summers are kinda warm (not yet!) but we occasonally have cool mornings that would make 20-50 a bit thick. I understand valve sticking, amoung others, is a possibility under these circumstances. Any ideas on the potential benefits of thicker oils in engines with over 140K mi? Thanks....

My Benz is a 560SL with 153K on the clock. The owner's manual specifies up to 20W50 for warm weather (down to about 32F minimum, IIRC). I use it, in the form of Valvoline's high-mileage-engine dino formula. Consumption is modest; I change every 3000 miles and find it's probably down about a quart when it's time to change. Consumption was notably higher with 10W30, which in my engine isn't recommended for summer conditions.

I'd start by looking to your manual for viscosity recommendations, then making your c