Advice on tires, towing and Baja please
I’m still relatively new to the travel trailer world. I’m hoping someone with more experience will check my reasoning and calculations regarding tow vehicle tires. My tow vehicle is a 2018 Jeep Grand Cherokee Ecodiesel Trailhawk 4x4. JGC towing capacity is 7,200lbs. We tow a 2019 Lance model 1985 dry wt 4,045 lbs; Carrying capacity 1,655 lbs; GVWR 5,700 lbs; tongue weight 500lbs; with tandem torsion axle; total length is 23’8 . I have read that you should keep the TT GVWR at least 20% (1,440lbs) below the towing capacity. The difference between JGC towing capacity and the Lance GVWR is 1,500 lbs which is about 21% cushion. So that seems safe.
We do take some longer trips, spend time boondocking, and do travel Baja California. We selected the JGC Trailhawk ecodiesel for towing and serious off roading. The Trailhawk comes with factory towing package which includes Class III factory receiver and bigger brakes. We added a REDARC TT brake controller and the equalizer 600 weight distributing hitch (tongue 600lbs, TT GVWR 6,000lbs). The JGC is set up with rock rails and will soon have a hidden winch and extra front skid plates. I know to subtract the weight of the winch + armor + tongue wt of 500 lbs. (estimating 700lbs total) from the vehicle carrying capacity of 1,190 lbs. That gives me about 490 lbs of people and their stuff. Most of the time it is my wife and I and our two small dogs. That leaves us about 100bs for gear in the JGC. Everything else has to go in the trailer.
The JGC GVWR is 6,800 (dry wt 5,326 lbs and 1,190 carrying capacity). The stock tires are Goodyear Wrangler Adventurer AT with Kevlar 265/60R 18 110T load capacity of 2,337lbs diameter 30.5” and they weigh about 40lbs. Total weight capacity of stock tires is 9,348 lbs. I read online that I should subtract 10% to get the actual weight capacity for metric tires. The net capacity of the stock tires would be reduced to 8, 413 lbs.
To improve off road capability and add stronger sidewalls to better handle rough Baja roads, I’m considering upgrading my tires to Nitto Ridge Grapplers 275/65 R 18 116TXL. Their load rating is 2,756 lbs and diameter is 32.09”. (This will fit without rubbing.) Total tire capacity is 11,024 lbs. Subtracting the 10% gives a net tire load capacity of 9,922 lbs. Since the GVWR of the JGC is 6,800lbs this gives me a cushion of 3,122lbs. I could go to a LT tire which bumps the combined capacity of the tires to 13,660 lbs. However, I think the ride would suffer greatly along with gas mileage (the XL tires weight 45lbs while the LT’s are 56lbs). Another negative is the stiffer sidewalls of the LT tires mean I will have to air down even more to get flexibility/flotation of the tire when I’m off road in rocky terrain or sand. I know the larger diameter changes the gear ratio, but other JGC ecodiesel owners are pulling larger TT’s with no complaints or concerns.
Is my math and reasoning correct regarding the JGC tire upgrades? If not please let me know where I’ve gone astray.
Now to the TT tires. The lance is about 10 months old and we bought it new last year. It is a 2019 year model. It comes with Goodyear Endurance ST 205/75/ R 14 105N D1. For those of you that take your trailer down rough asphalt roads like in Baja, do you think this tire is up to the task or should I upgrade? What tire would you upgrade to?
Thanks for taking the time to read this.
We do take some longer trips, spend time boondocking, and do travel Baja California. We selected the JGC Trailhawk ecodiesel for towing and serious off roading. The Trailhawk comes with factory towing package which includes Class III factory receiver and bigger brakes. We added a REDARC TT brake controller and the equalizer 600 weight distributing hitch (tongue 600lbs, TT GVWR 6,000lbs). The JGC is set up with rock rails and will soon have a hidden winch and extra front skid plates. I know to subtract the weight of the winch + armor + tongue wt of 500 lbs. (estimating 700lbs total) from the vehicle carrying capacity of 1,190 lbs. That gives me about 490 lbs of people and their stuff. Most of the time it is my wife and I and our two small dogs. That leaves us about 100bs for gear in the JGC. Everything else has to go in the trailer.
The JGC GVWR is 6,800 (dry wt 5,326 lbs and 1,190 carrying capacity). The stock tires are Goodyear Wrangler Adventurer AT with Kevlar 265/60R 18 110T load capacity of 2,337lbs diameter 30.5” and they weigh about 40lbs. Total weight capacity of stock tires is 9,348 lbs. I read online that I should subtract 10% to get the actual weight capacity for metric tires. The net capacity of the stock tires would be reduced to 8, 413 lbs.
To improve off road capability and add stronger sidewalls to better handle rough Baja roads, I’m considering upgrading my tires to Nitto Ridge Grapplers 275/65 R 18 116TXL. Their load rating is 2,756 lbs and diameter is 32.09”. (This will fit without rubbing.) Total tire capacity is 11,024 lbs. Subtracting the 10% gives a net tire load capacity of 9,922 lbs. Since the GVWR of the JGC is 6,800lbs this gives me a cushion of 3,122lbs. I could go to a LT tire which bumps the combined capacity of the tires to 13,660 lbs. However, I think the ride would suffer greatly along with gas mileage (the XL tires weight 45lbs while the LT’s are 56lbs). Another negative is the stiffer sidewalls of the LT tires mean I will have to air down even more to get flexibility/flotation of the tire when I’m off road in rocky terrain or sand. I know the larger diameter changes the gear ratio, but other JGC ecodiesel owners are pulling larger TT’s with no complaints or concerns.
Is my math and reasoning correct regarding the JGC tire upgrades? If not please let me know where I’ve gone astray.
Now to the TT tires. The lance is about 10 months old and we bought it new last year. It is a 2019 year model. It comes with Goodyear Endurance ST 205/75/ R 14 105N D1. For those of you that take your trailer down rough asphalt roads like in Baja, do you think this tire is up to the task or should I upgrade? What tire would you upgrade to?
Thanks for taking the time to read this.
