88 560 SEC oil weight question
 

20W-50, Castrol GTX High Mileage, is that okay for my car with 161,000 miles in it? I am going to take it in and have it changed but bought the oil and filter and just want to confirm that this will be okay for my car. I live in Miami and it is obviously on the warm side. Also, I drive the car once a week.

Thanks - Lance

i keep 20w-50 dino in two of my cars for the summer. the 300ce and 260e

my sons 300e has 15w-50 synthetic. His top end had been rebuilt and doesn't burn but maybe a half quart inbetween changes.

20w-50
 

I used it in the summers in Denver, CO, and here in The Swamp in my 420SEL. The gas mileage was nothing to crow about, but then it never was. The 20W-50 is fairly thick, so you might see a mileage hit.

I did notice that my hot oil pressure on the gauge read a bit lower with the 20W-50 than with the gas/diesel rated Chevron Delo 15W-40 I switched to during the W126's last years. Not a lot -- 1.6 bar (I'm estimating) vs. 2.0. (The brand of 20W-50, Valvoline, might have had something to do with it, since there's variation in hot viscosity among brands, even within the identical grade.)

Castrol 20-50
 

Best thing I ever did was switch to Castrol 20-50 High Mileage in my 1990 560 SEC Florida car, Zero oil consumption since switching. This oil is specially formulated to keep/restore seals used in older cars.

Oh boy, another oil thread. Let's see how long before the vitriol starts flying...