My 1994 960 has about 252K miles. I've put 100K on it since I bought it not quite 3.5 years ago. I've always tried to keep up with routine maintenance, mostly not me but my independent Volvo mechanic.

I've had the timing belt replaced 3 times including right after I bought it not knowing the last time it was replaced, and every 50K thereafter. Also have had the transmission fluid flushed 3 times, once right after I bought it with about 152K miles on it and most recently a couple of months ago, always using the Gibbons method aka open the return line and catch the fluid in a vessel as you run the car, keep refilling and flushing through until clean. I always provided the fluid for my mechanic to do the job, using a brand name Dex3 compatible fluid.

This last time I happened to mention before I bought fluid that I'd like to have it flushed again. My mechanic suggested Valvoline Max Life High Mileage Synthetic ATF fluid. See the picture below. I have to say after driving it for a couple of months, WOW, I am amazed at the results ever since it was changed and to the present day. It was never bad before but did have the occasional quirky shifts at times especially in hot weather and after the fluid got hot. I have noticed a difference now having always consistently good shifts in all gears under all conditions, including now that we've had some very warm days where I live. The little quirks with almost a little bit of slipping as it shifted from third to fourth gear on occasion is completely gone.

Not only that, but my car is noticeably more peppy for the first time in over 3 years and over 100K miles I've put on it. It literally climbs hills with more torque meaning it pushes up hills easier and in higher gears with fewer downshifts necessary. Not that it was bad before, I just noticed an unexpected improvement in driveability. And this might sound crazy but it absolutely accelerates better getting onto the freeway. I don't have to push it as hard to get up to 60 or 70 MPH like on the freeway on ramps. I would never have believed it had I not experienced it. My car has always run well. It's always been more peppy than a standard 240 of which my friend has owned 4 of them and I've driven them all. I've had a NA 850 and a turbo V70 XC but I had never owned a Volvo 6 cylinder so I didn't have any experience to compare this car to. I was satisfied before but very happy now. I would highly recommend this fluid for an older Volvo with an Aisin Warner 4 speed automatic, or at least for an AW30-40 like I have. It feels like it literally breathed new life into my car and perhaps is extending the life of my transmission.