# Weight in rear

There’ve been a couple of questions about how much weight to add to the rear for snow and ice driving with rear-wheel drive cars and pickups. There’s got to be an optimal weight distribution (or range) and that can be calculated. So, lets have some science (or at least engineering) here.

I don’t think you will find science involved in this discussion,just “this is how it was for me” type of posts.

My suggestion is not to start putting additional weight in your car or truck. Additional weight means you have more mass to stop. I suggest getting a set of four winter tyres and drive safely.

If you really want to know what works for your cars, get a stack of sand bags and find a open parking lot with lots of snow and ice, then experiment. Don’t expect the same results with two different cars.

I was surprised Tom and Ray didn’t admonish the caller to secure the weight over the axles so it doesn’t become a projectile in a collision.

When you consider that a pickup is designed to carry weight in the back, you have to know that the ride improves along with the traction. About four to five hundred pounds is enough. Even a plastic cover over the bed will improve the ride. Camper shells are out; you could lose three miles per gallon. You can’t calculate the amount because there are too many variables, starting with tires. Rear wheel drive cars will eat the rear U-joint if the pinion angle is too straight; and they don’t need as much weight anyway. About a hundred pounds and experiment from there. That is really all the science needed.

Get 4 snow tires first. I like Blizzaks. You can get them mail order on rims from a place like Tire Rack, and UPS will drop them off next to your truck.

I’ve always had a cap on my truck. I don’t know the science on gas mileage with or without. In any case, it adds weight distributed over the axle.

I still carry sand, in a secured sheet-rock-mud bucket. You can always use it under your wheels for traction if you keep it dry. Or you can carry kitty litter, which is light.

Carry a shovel.

How did you arrive at the idea that a camper shell will cost you three miles per gallon??? According to my and some of my friends experiences, the added weight is off set by better aerodynamics.

Some wind tunnel experiments and on-road experiments have shown less fuel economy with a shell. Someone posted a link here to an article about it. I wish I could remember who it was. I think the article may have been in Popular Mechanics. It was actually an article about whether or not to put down the tailgate, but they also tested the trucks with a few different types of shells.

Anyway, based on what I have seen, the results from studies have been mixed based on who is funding the study. If the company that makes and sells the shells is funding the study, you can bet it shows better fuel economy with the shell on.

Too many variables…but generally it’s trial and error. How much economy are you willing to give up ? I took a Sidekick and added over 500 lbs on the rear axle as a test. It was an animal on ice and snow but one scary piece of machinery on the road at speed.

I suggest you get some “tube sand”(plenty) and do your own trials in slippery conditions (safely). None of the added weight as stated will help as much as appropriate tires.

To sytap8. Reread. Could lose three miles per gallon. Could lose less, could lose more. Most shells are higher in the rear than in the front to give you more clearance for loading. Knowledge is power.

That is a good point. Some shells add to a truck’s aerodynemic profile if they are taller than the truck is without a shell. Those types would definitely have a negative effect on fuel economy.