Hello All,


If this issue has been discussed before, I apologize. At what mileage intervals should you change the oil and oil filter? I have 2 1996 850 wagons, non-turbos with 5 speed manuals. One car has 270,000 miles and the other 200,000. One car I got new, the other when it was 3 years old with 50,000 miles on it. I also have a '99 XC which I bought used with 12K on it and which presently has just over 94K on it. I have changed the oil and oil filters on all these cars at 5,000 mile intervals. On previous cars, an old Volkswagen Beetle and several Asian cars, I changed the oil every 3,000 miles.

When I got the Volvos I jumped to 5,0000 mile intervals. This was due to what the owners manual said in the 850s: change the oil every 10K or at 5K if the car was involved in heavy duty use or adverse conditions. The cars are not used in heavy duty use or adverse condition Also, a few years ago Consumer Reports did a report questioning the necessity of changing oil every 3K which was a popular rule. CR took a fleet of new Chevy Impala taxi cabs and broke them up into two groups. Those that had their oil changed at 3K intervals and those that had it done at 6K intevals. After racking up 60K plus miles, it broke down the engines to check for engine wear. It found minimal differences, but not critical, between the two groups of cars. CR attributed the lack of difference to the fact that currents oils are far more efficient at protecting engines from dirt and combustion byproducts than oils of a few years ago, when the 3K change interval was recommended.

Recently, my independent mechanic, who works exclusively on Volvos told me I'm doing a disservice to my 850s, that I should change the oil at 3K intervals (certainly not let it go more than 3,500 miles). I use conventional motor oils on my 850s and Mobil 1 on the XC. He said it was "OK" to change the oil on the XC at 5K intervals becaue I was using a synthetic. I confess, I respect his opinion.

Both 850s don't seem any worst for wear, but I'd like to hear the thoughts of others on this topic. Thanks to all who respond.

Hugh