Hi guys,

My 850 used to run on diesel oil until I got it then I switched over to full synthetic conventional. Now the car consumes oil. So, is it fine to run the turbo engine on diesel? Will it affect emissions in any way? Being in California very strict in that area.
Thoughts.....

 

Diesel oils have a different composition from conventional car oil so stay away from them. Oil consumption when switching to synthetic is normal on an engine with miles. The oil seeps better for a given viscosity so more of it gets into the combustion chamber and through worn seals. Honestly, as long as you run Castrol or Mobil1(preferably Castrol) you're fine. If you're worried about consumption, get a viscosity modifier called HyperLube Smoke fix. It works very well in my personal experience at sealing up old, worn rings and seals. It slowed my consumption to over half what it originally was and I have a slightly low cylinder(150 vs 170 on all others w/ normal oil) and it actually boosted running compression amazingly. I'm not affiliated with HyperLube in any way either.

 

"as long as you run Castrol or Mobil1(preferably Castrol) you're fine."

And what's wrong with the rest of the synthetics or what is so good with just those two ?? I like Valvoline myself but for no particular reason and I'm not above grabbing a "house" (Autozone, Oreilly, Napa, Walmart) brand when they have a good sale on it. If you can't afford Mobile1 the house brands are still better than the blends or conventional

 

Depending on the diesel oil, it could be better if it still has zink in it. That's one of the "pollutants" they pulled from regular oil and it's hard on lifters and cams without it. You can buy it separately for "break in" or just add it to high performance engines at the change interval. Depends on your cam geometry, the more radical the more it can help protect your valve train.

I've run diesel oil in both my 850 turbo and 454 Chev Madza.