Thanks for the help so far. Here is some more information. First off - Yes - I know my 854 Turbo with 222 hp will go a lot faster then my 745 Turbo with 160 hp. Only makes sense.

The thing is... I ran 91 octane for the past 8 months (since I had the car) and I have only ever been able to get 200 miles out of a tank of gas. My math in the first post was off so my mileage is more like 16 or 17 mpg. I have seen many posts all around 22 mpg on this board.

So last week I was going to get gas and the options were Petro Canada 79.9 cents / litre (for premium) or Sunoco at 65.4 (87 octane). I suppose I could have gotten premium at Sunoco but I didn't - I got the 87 octane. What did I notice? I suddenly could spin my tires when the car shifted into second, I could accelerate on the highway very fast, the throttle was very resopnsive even without getting into the turbo etc. Also I got 220 miles on that tank. Not a whole lot better but everyone else always posts poorer performance and mileage with 87 octane. I am now on my second tank and I still see the same effects. Overall the car runs very well (likes to stall once immediately after start and then runs perfect next time). It has 170000 miles on it. It has new plugs, air filter, no foam in the air box, new cap and rotor.

I am convinced that this has to be a timing issue. Possibly my timing is very retarded. I have not now or never noticed any pinging so I think this may be the case. When i got the car there were many vacuum hose problems including the one to the turbo that goes over the enging was melted to the exhaust manifold. Maybe there was pinging and someone just adjusted the timing instead of figuring out why. In any case - I am just looking for a second opinion. I may go out and buy a timing light to satisfy my curiosity.

BTW - Does anyone have the exact steps to set the timing on a 88 745 Turbo? It's probably in the FAQ right ;-)

Thanks in advance
Another volvo lover...