I have an '86 740 GLE with (4) new Blizzaks and (4) 70 pound sand bags in the trunk, yet the car seems too heavy upon acceleration and the rear seems to sag a bit. My question is, how much weight do my fellow RWD drivers usually put in their trunk during winter.
Is 280 pounds too much???

Fred - I've owned 4 740s, and am currently driving a 1990 740 Turbo in Massachusetts. (I do have studded snows.)

The only sand that ever got in the back of my cars got vacumed out twice a year or so during my annual spring and fall cleanings.

We have 4 drivers in the family and none have ever complained as long as the cars had 4 decent snows on them.

While I do not add weight, I would admit to carrying full size spare tire, and usually 35 or 40 pounds of tools and spare parts.

See if your car does anything funny on a straight but slippery road, or in a large parking lot if you accelerate hard or apply the brakes hard. For the most part, your car should track fairly straight, if not, you might need to check all four wheels' alignment.

Last winter my cruiser would pull to the right under acceleration, and pull to the left under braking. In really slippery conditions and at speed, this was quite exciting!

Turned out that one side of the rear axle was loose and moving back and forth due to torque forces.

With 4 new Blizzaks, IMHO you don't need any additional weight. The tires will get you started and once moving, extra weight creates more trouble than it solves. More weight means more inertia in stops and turns.

Skip
'83 240TI (with 4 Blizzaks)
'93 850GLT
'96 850R

Fred:

280# in the trunk will cause more problems than it will solve.

First of all, the best place for weight is in the footwell of the back seat. Putting it in the trunk over the axle is the next best place, but it will tend to slide around in the event of a sudden change of speed or direction.

The advice for one 70# or 80# bag of sand, and a matching bag of salt, or 2 bags of the same should be quite sufficient. We just got 10 inches of snow here in central Virginia, and I had no trouble once I put 2 70# bags of sand in my rear footwell, despite the crappy snow removal here in the South.

If you have all that weight (280#) in the trunk, and your rear end breaks loose, the moment of intertia created by having that weight in the back could cause you to spin around like crazy, which would not be good.

Fred, I put 100 pounds.
absolutely helps without being a burden on the springs or the accceleration.
--
'75 Jeep CJ5 345Hp ChevyPwr, it wasn't safety , it was Longevity

I would go 140 pounds max....it's not like some straight line relationship. You just need enough to get that extra bite (you may be amazed how little weight helps sometimes like 3 gallons of WS squirter juice (25#'s)) and more is NOT better....

DUDE!

Yes, you are carrying WAAAAAAAAAAY too much weight in the back. Anything over 100-120 lbs extra on the rear axel will only undermine performance. Additionally, should you get in a spin the massive weight you are carrying is going to toss you around like a rag doll, throwing off the weight distribution of your volvo.

I woulkd scrap ALL your bags and go pick up a 50lb bag of rock salt and a 50lb bag of sand and place them side by side on the rear axel. Not only is this the perfect weight combo for the snow, but the salt and sand can help you should you find yourself in an icy or snowy situation.

Never had one that new but with regular tires in a 122 wagon and a 164,
I don't put any extra weight in the trunk and do fairly well. When you
get into a spin, extra weight in the trunk will make the trunk lead the
car. (at least a LOT of extra weight in the trunk will).
Even in the front-heavy 164 I find I can climb hills that front wheel
drive cars have problems with. Of course getting a run up them helps
a lot. Don't ever stop at the BOTTOM of a slick intersection - coast through
it as fast as you safely can, conserving your momentum for when you need it.
--
George Downs Bartlesville, Oklahoma

The 700 series is notorious for traction and snow problems, and extra weight helps keep the rear end down in the snow and increase contact/decrease slipping, although you are right on with 280lbs being WAY to high.

If you think of how the 700 weight distribution is laid out in relation to its suspension you can see why it doesn't do well in snow (without serous snows and some exttra weight to hold oit down).

FYI, I'm in Vermont on a ski mountain with my 745t and we just got hit with 14". I took my car out in about 3"+ and couldn't even come CLOSE to getting back up to my house. Time for some new snow tires... and I haven't bought my 50lb bags yet for teh back... oy.

-Rick