How Important is Weight Off-Road?

How important is vehicle weight when off-roading? For example, if I have 2 otherwise identical pickup trucks but one weighs 4k lbs but has less torque and the other 6k lbs but has more torque, will they perform differently when going over obstacles? Will there be some obstacles that the 6k lbs just cannot climb over or steep inclines where the 6k lbs truck get beached while the 4k lbs truck just plows though?
Because I've heard that lighter is better off-road but I'm not sure if that's just because it lessens the probability of breaking something and also because a lighter vehicle is easier to recover should it get stuck, or if there could actually be a situation where just the weight alone causes a vehicle to not be able to overcome an off-road obstacle that would have been not much of a problem with a very similar but lighter vehicle?

 

Generally, lower weight means higher performance and less stress which contributes to increased reliability and durability given that everything else stays the same.

Then, there are several other aspects to consider, some of them are power-to-weight ratio and gearing. The 4k-lb truck in this particular case would likely be a better choice.

I'm not an avid offroad driver, but I have been in several outings and small, light, low-powered vehicles like the Suzuki-Geo crawling all around much heavier vehicles with much larger engines. This is not a completely fair comparison because there are other favorable aspects (not just a lower weight and a less powerful engine), but it is enough to see the difference.

 

Try pulling a 3/4 ton crew cab diesel out with your Tacoma DCLB you'll have your answer pretty quick

 

One weight item that would help you overcome an obstacle is for example a winch bumper and a winch, but like with everything, am I really doing to need it? I've built a Jeep TJ and I've purposely kept weight down and not done some things that have forced me to do other things. Weight matters with altitude, climbs, getting around obstacles, stress on other components, mpg, and just getting to trails and not being a slug on the highway. I'm following the same idea with my Tacoma, also being that I want to keep it's already low payload as high as possible since it does after all has a truck bed. Last, with my Jeep, it has a winch and frankly I hate using it.

 

I look at it as a give and take. Each modification to your rig should give you some advantage or practical application, but always consider what it might take in return. My rule of thumb was to keep it as light as possible. When I had a wrangler, built to be as light as possible besides the larger tires, it was climbing slopes and bumping up over obstacles that the heavier rigs needed to winch up. Seems to me that one "mod" that’s often neglected by many folks is the ability to pick the best line on the trail for YOUR set-up. With that skill, most people would never need most of the armor they weigh their vehicle down with. Just my .02

 

I'd say it depends.

Back when I went off-roading all the time, a buddy of mine used a tahoe, while I had my truck. Both were 4x4's and had the same tires, but the Tahoe had a harder time. Some turns were difficult to make in both vehicles, but the loss of weight in the rear of the truck helped. Tree stumps usually nudged my rear end over and helped me, while the Tahoe had to do a 30-point turn just to make it.

 

Classic apples and oranges.

Your title speaks to weight.

Your question mixes weight and torque.

Pick one or the other.

Or you can assume a torque/weight ratio that's equal between vehicles, but you would have to assume the torque is generated at equal RPMs to evaluate properly.

But it's safe to say that less weight and more torque are both winning items.

 

There's also a relationship between a tire's coefficient of friction and the normal load applied to it. Typically the coefficient of friction for a tire decreases with normal load. This means that a lighter vehicle has a higher total level of grip relative to its weight. This is why lighter vehicles, in practice, are slightly more capable/faster than a heavier vehicle if neither are power limited. This is also why race cars have higher total levels of grip during cornering and braking when normal load is distributed most evenly between the 4 tires.

 

on trips, i weigh in at over 6300lbs... so far so good... but that's all i got to say about that.
Stock suspension lasted me like 6 months lol

 

Don't mix weight and torque because they are totally different conversations.
However,
A lighter truck is always better for off road. Less ground pressure.

Now, remember this... A vehicle's maximum deliverable torque is when you break traction.

For example, I can design a vehicle that has enough torque and power to go up a 45 degree slope but, if I have wheel spin at 30 degrees, whatever torque and power is required to spin is the max torque deliverable.

BTW, the angle of repose of rocks is 37 degrees so my above example is hypothetical at best. (angle of repose is when rocks will overcome gravity and roll down hills lol)

 

I have to disagree with you there my friend. Think farm tractors. Big heavy vehicles with skinny tires in the front and rear.
It does have a lot to do with tire coefficient of adhesion but it has more to do with ground pressure. There is a "sweet spot" for off highway vehicles and this is dependent on the ground conditions the vehicle will be operating on regularly. For example, if it's a marsh you need a lot of contact with the ground (big wide tires) versus hard rock where you can go with skinny tires.

 

I usually leave the gf at home when off-roading to save weight .... don’t tell her that lol

 

I'm not taking about tractors nor specific surfaces. I am talking about known and understood tire data. All things being equal, a lighter vehicle has more tractive force available relative to its weight. Yes, that will only be helpful to conquering obstacles, and never a hindrance.

 

Alright there, whatever you say boss.

 

Keep the weight low, over the axles. Top heavy is no good for any vehicle, especially an off road vehicle. I always laugh at people who put the spare on the roof.