I've had my 122 wagon for about a year, and have mostly puttered around my neighborhood in it. It has a stock B-18 with a M-40 tranny. Today, I decided to drive it to work, all highway, distance about 16 miles. When I get it up to about 50mph (real speed, not the indicated speed) the engine noise is overcome with a lot of noise that increases with speed. When you hold constant speed the noise stays, and upon coasting, it's there until my speed drops to about 50mph or so. My problem is that I do not hear certain frequencies very well, and thus I can't really identify what it is or where it's coming from. Now my first thought is driveline noise, but I just replaced all U-joints, and the center bearing, as well as the center support rubber. I marked all pieces before so I would put it back the same way. I know I get a little noise that I can identify from the rear end, but it has at least 184k miles on it, so I think it is normal wear. The rear end noise seems to disappear when I get above 35mph or so. My contention is that at (real)speeds of about 65-70mph, the noise is REAL loud, almost painfull. Are wagons supposed to be this loud? What is the safe maximum speed for a wagon without an overdrive? Also, unless my fuel gauge is wrong, I used about 1/4 of a tank to drive about 32 miles! I've tuned it and it runs great, and the plugs look good, so what's up with that? Sorry about all these questions, but I don't know any old Volvo folks around here. Any help will be greatly appreciated!