Grease Monkey Report...

[Tobert]

I am burning oil and need to add some, should I stick to 15w-50 or could I put 5W-30 in? Will it hurt to "mix" the two?

Mixing is fine, but to be safe stick to the same brand of oil. In the old days, there were certain oils that were bad to mix, supposedly because of differences in base crudes having chemical reactions. This could be an old wive's tale though. I've been broke and had to do it and never had any problems. In fact, I've purposely mixed oils to increase or decrease the thickness. My Jimmy had really low oil pressure after putting 10w30 Napa synthetic in it. I added some 20w50 Valvoline Synth somebody had given me and got it into acceptable range. It's not a good practice, but works in a pinch.

[nfpgasmask]

Cool, thanks. Actually, despite all the Jiffy Lube horror stories on here, the guys at the one I went to were super cool to me, and actually gave me three quarts of Mobile 1 15-W-50 for free after we talked for a minute about the truck's oil consumption. But alas, free oil and friendly customer service does not mean they knew how to operate under my VX.

Bart

Mixing is fine, but to be safe stick to the same brand of oil. In the old days, there were certain oils that were bad to mix, supposedly because of differences in base crudes having chemical reactions. This could be an old wive's tale though. I've been broke and had to do it and never had any problems. In fact, I've purposely mixed oils to increase or decrease the thickness. My Jimmy had really low oil pressure after putting 10w30 Napa synthetic in it. I added some 20w50 Valvoline Synth somebody had given me and got it into acceptable range. It's not a good practice, but works in a pinch.