I just mixed 2 1/2 qts. of Chevron Delo 400 15w40, 1 1/2 qts. of Chevron
10w30, and 1/2 qt. of Shell Rotella T 5w40 synthetic.  This is with a 1.8 l.
RV inline four.  When I do something like this I monitor it at the dipstick
after each ride until I'm satistied that all's well.

Dana

On 24 Sep 2003 at 10:24, Matthew wrote:

> I changed oil last night but I had to use oil that was left over from
> other oil changes. It was all new oil but some was 10W-30, some was
> 20W-50, and the other was something else in viscosity. All was the same
> oil mfg...quaker state. Is there any problem with mixing viscosities as
> long as the oil is the same mfg?
>
> -matthew, a chemist at that!
>