Can I go from Synthetic back to regular oil?

Certainly. I feel synthetic is worth the premium, but other people don't. It's your choice.

Mike

You can, but with an add-on turbo installed I would stick with synthetic. Turbochargers can be very hard on oil.

Now if it was a stock engine I would say sure, no problem!

John

FWIW, our '85 Volvo just turned over 238K miles on the original turbo, even though I never could convince my wife not to gun the engine when starting and to let it idle when she pulled off the freeway into rest stops. It ran on dino oil the first 20 years or so, and I just changed it to synthetic a year or two ago.

That said, I think I've been mighty lucky. Water cooled turbos are pretty sturdy, but treating it right is cheap enough. Synthetic gets my endorsement, but do as you wish.

Mike

I dont want the turbo, I am using as a work car and have the turbo turned way down. I am looking to trade it on something else now. I dont run it hard, just up and down freeway to work everyday mostly. I think a seal is leaking in the turbo as I am blowing black soot out the back and makes a white bumper really nasty. Turning it down helped some but still smokes on acceleration.

In my limited experience, turbo seal failures result in shocking billows of blue smoke filled with oil mist and oil consumption measured in gallons per hour. The black smoke makes me wonder if there is a mixture control problem; adding a turbo requires some means of richening the mixture during boost to suppress detonation, and that may not have been done right. I bet if you look at the plugs you will find them sooted up.

Mike

I know it has aftermarket rail and higher cc injectors, plus a Hondata chip.