Mid Grade Gas in Turbo?

[Ozark Lee]

When I pulled into the station last week and found 91 premium at $3.10/gallon I went for the 89 mid grade on the Platinum. I felt like I violated it but it ran OK.

As has been said, running 87 octane regular in a turbo is tough on the exhaust valves.

...Lee

[XxJenoxX]

Honestly, I haven't been running anything but high test in my n/a. I mean, what do you really save, $2 a tank compared to regular??? And you're not really even saving, since the high test fuel burns slower and cleaner.

[polskamafia mjl]

I never go below 89 for my NA. I've heard too many stories of burned exhaust valves with 87.

[1997volvo850]

My 850 owners manual specifies 91 octane or better.

We were putting in regular for a while because we didn't realize our 850 was a Turbo.
In rereading the manual I ran across the specification for > 91 octane gas. I now
use only 91 and above.

What are the symptoms of burnt exhaust valves? Will using > 91 reverse this damage?

[polskamafia mjl]

Symptoms of a burned valve would be rough runnig, loss of power, low compression. A burned valve is essentially a valve that has heated up so much it no longer creates an air tight seal. You can't reverse the damage, only prevent more from happening. You can replace the valve, but that is a bit involved.