In the August issue of Jp we introduced Trasborg's latest harebrained scheme: building a Jeep that can both wheel and get decent mileage on the road. In Part I we dealt with a lot of problems typical of higher-mileage vehicles, put on bigger tires, and started looking at a cooling issue.
Once we got done with that, we turned our attention to the soft underbelly of the Jeep. Unlike Wranglers, Cherokees don't ship from the factory with skidplates or recovery points as standard fare. If you want skidplates, you have to order them, and even then you get some thin, 11-gauge steel that barely covers the vital components. Since we were at stock height, we knew we'd be hitting something important off of some rock sooner rather than later, and decided to armor the Jeep before we damaged it. And it was a fair bet that we'd need to get yanked off of whatever our new skidplate was resting on.
In the last 15 years of playing with Jeeps, we've heard that for every 100 pounds you add or remove from a vehicle, it's like losing or gaining 5 hp, respectively. So we decided to test the theory out. Whatever numbers you subscribe to, it stands to reason that the more weight you add to a vehicle, the more effort it will take for the engine to move said vehicle, and you'll lose fuel economy.
But on a Jeep as short as this one, every bit of armor will help us get off the trail and back home in one piece, so we weighed all the parts we added, and over the last 5,000 miles have been watching what the added weight does to our fuel economy. What we found was that it really didn't do as much as we thought it would.
With no real frame to bolt...
With no real frame to bolt a towhook to, Jeep added brackets that run down the unibody and tie into the bumper, which the towhooks then bolt to. We didn't want to spend a fortune because we plan on upgrading the front bumper later, so we hit the junkyards looking for towhooks and brackets. We found the brackets, but only on early XJs. The bumper for the later XJ is different, and we had to weld the late-model mounts to the early towhook bracket to make it work.
One of the first things we...
One of the first things we did was add a set of Treks Offroad Equipment unibody stiffeners to the Jeep. Then we put in a Treks bellypan to cover the NP242 that hung almost 4 inches below the uniframe. Both are made from 3/16-inch plate steel and add a ton of rigidity to the unibody.
The stock 200,000-mile seats...
The stock 200,000-mile seats just weren't cutting it anymore, so in more junkyard scrounging, we wrangled up a set of '00 Grand Cherokee seats. We didn't want the leather, per se, but they are really comfortable and in way better shape than what we started with. Our XJ had a power driver seat, but the passenger seat was manual. The power seats are quite a bit heavier than the non-power models, but worth it in the end.
We added this tire carrier...
We added this tire carrier from an '84 XJ to get the tire out of the cargo hold. With some welding and cutting needed, it isn't a bolt-on, but works for the time being. We also found a factory front skidplate in the junkyard that protects the drag link and tie rod. A trailer hitch from a '97 Cherokee gave us a recovery point in the rear.
With the Jeep as low as it...
With the Jeep as low as it is, we wanted the best possible clearance under the doors, and that meant cutting out the stock rocker and replacing it with thick tube. Gen-Right Off Road has a builder's kit which is just the steel needed to make these rockers, and you weld it together yourself; normally $299, we bought the kit on sale for $249. If we bought the steel from our local steel supplier, it would have cost us more than what Gen-Right charges.
Finding a gas tank skidplate...
Finding a gas tank skidplate for a late-model XJ in the junkyard just wasn't happening. The factory skid isn't the best to begin with, but it sure isn't worth the $100 people were asking for it in used condition. We found that Gen-Right was making a 25-gallon replacement tank that came with a 3/16-inch skid. So not only did we ditch the melting-prone plastic tank, we gained almost 100 miles of cruising range thanks to the bigger tank.
Unfortunately, the extra weight...
Unfortunately, the extra weight out back, the added weight of the extra fuel, the skidplates, and one off-road-based camping trip were all that our 200,000-mile springs could take. We cobbled together a bastard pack from a set of stock Metric Tonne MJ springs we had lying around. We ended up with almost 2 inches of lift, so we added a spacer out front to come close to leveling it out. We didn't get any change in mileage from the added elevation.
Added Weight
First 5,000 miles: 15.7 average mpg
Treks belly skid: 60 lbs
Treks stiffeners: 35 lbs
Gen-Right rockers: 100 lbs
Gen-Right gas tank: 60 lbs
Spare tire swing-away and brackets: 42 lbs
Towhooks: 21 lbs
Front skidplate: 18 lbs
WJ seats (weight over stock): 40 lbs
Trailer hitch: 50 lbs
Receiver mount shackle: 20 lbs
Total weight added: 446 lbs
5,000 miles with armor: 15.4 average mpg