Wednesday, February 1, 2023


How to increase the longevity of your tow vehicle

By Mark Polk, RV Education 101
When you spend fifty thousand dollars (or more) of your hard-earned money for a tow vehicle, you don’t intentionally abuse the vehicle. But sometimes we abuse the vehicle without knowing it. For example, if you don’t have the proper hitch setup and too much weight is resting on the hitch ball, you put more burden on the tow vehicle. Another example is not monitoring, or maybe not knowing, what temperature the engine, transmission or other components are operating at. Heat is your tow vehicle’s worst enemy.

So where do we start when it comes to increasing our tow vehicle’s longevity? Good question. Let’s start with the basics and go from there.

How much can the tow vehicle tow?

Before you lay your cash out make sure you know how much the vehicle you plan to purchase can really tow. What does that mean? It’s unfortunate, but lots of SUV and truck salespeople don’t really know or understand what a vehicle’s tow rating is. To complicate matters more, truck manufacturers offer hundreds of configurations across the truck and SUV lines they sell. You can take two trucks that are identical in model, year, cab configuration, engine and transmission, and the tow capacities can be thousands of pounds different. It’s hard to believe, but it’s true.

There are several factors that contribute to this. The most common, and perhaps the least understood, is the rear axle ratio. The ring and pinion gears used in an axle (or final drive assembly) dictate if the vehicle is better for fuel economy or for towing. If you purchase a truck to use as a daily driver you want to maximize fuel economy. On the other hand, if you purchase a truck to tow a trailer or haul heavy loads on a regular basis you want a good towing axle. There are axle ratios that offer a compromise between fuel economy and towing. It’s easy to see why this is such a confusing topic. When you purchase a tow vehicle make sure it has a rear axle ratio that can get the job done.

Gas vs. diesel

Another consideration is gas vs. diesel. Engine and transmission technology continues to advance, and there are lots of good gasoline engine, transmission, and axle combinations available for towing a trailer, but diesel engines are still predominant in the towing marketplace. The main reason is torque, or raw pulling power. The torque produced at lower RPMs is ideal for moving heavy loads. Torque increases towing capacity, and the Gross Combined Weight Rating (GCWR) of the tow vehicle. The GCWR is a term you seldom see or hear about but is extremely important. The GCWR of a tow vehicle is the maximum allowable combined weight of the fully loaded truck and fully loaded trailer. Regardless of whether it’s gas or diesel, the GCWR is a crucial rating to consider when you purchase a tow vehicle. Another consideration is cost. The cost of trucks continues to increase, and diesels even more so than gas.

Matching tow vehicle and trailer

After researching, selecting, and purchasing the right tow vehicle for the job you need to select a travel trailer or 5th wheel trailer that doesn’t exceed the vehicle’s tow rating or any other weight ratings on the tow vehicle. I have written entire books on this topic alone because there are so many variables, but to keep it simple I suggest you purchase a trailer that has a Gross Vehicle Weight Rating (GVWR) that is equal to or less than the tow vehicle’s tow capacity.

What this means is, if the trailer is loaded to its max capacity (GVWR) the tow vehicle is still rated to tow the trailer (at least on paper). I do need to add a disclaimer here: You still need to make sure weights do not exceed the vehicle’s payload capacity, gross axle weight rating (GAWR) or Gross Vehicle Weight Rating (GVWR). The tow vehicle and trailer both have these individual weight ratings that cannot be exceeded. And don’t forget about the GCWR I mentioned a moment ago.

Proper hitch components

Next, you want to make sure you are using the correct hitch components to tow the trailer safely and properly. You can write a book, or at least a chapter, on this topic too. First, it is important you understand every component in a hitch system has a weight rating. This includes the hitch receiver on the truck, the hitch ball, ball mount, and any weight distributing hitch system you use. Proper hitch components are a good start, but only if the components are used correctly.

If you put too much tongue weight on the hitch ball you not only add stress to the tow vehicle’s drive-train, but it also affects the steering and handling of the vehicle. I recommend going to a service facility with properly trained technicians to set the tow vehicle and trailer up for safe towing. Make sure you thoroughly understand how to hitch and unhitch the trailer prior to leaving the dealership because it will be your responsibility to do it correctly from that time on.

With the onset of the SAE J2807 towing standard and the increased popularity of RV camping, truck and SUV manufacturers are refining technology that results in better towing design and capabilities. For starters, when you purchase a vehicle with towing in mind, you want to make sure the vehicle is equipped with a towing package option. A towing package typically includes items like a hitch receiver, 7-way trailer light plug, transmission oil cooler, heavy-duty suspension system, towing mirrors, and heavy-duty cooling systems.

Manufacturers today include innovative technology like electronic trailer sway control, integrated electronic brake controllers, tow/haul transmission modes, auxiliary braking systems, advanced air ride suspension systems and multi-view camera systems. So, it’s easy to see why a tow package option is essential equipment.

Monitor temperatures and gauges

Having the right truck, trailer, and hitch components is extremely important, but towing heavy loads puts a strain on the tow vehicle’s drive-train. One result of towing heavy weights is fluids in components like the engine, radiator, transmission, and rear axle running hotter than normal. This increased heat can cause a component to overheat or reduce the lubrication necessary for the component to operate properly. It is essential for owners to monitor gauges and be aware of what normal temperatures are, so you know when a component is running hot.

If you are not in the habit of monitoring gauges, try to make a conscious effort to do so. Another problem is some vehicles don’t have gauges to monitor components like the transmission and rear axle temperatures. If you plan to tow a trailer often, or under extreme conditions, it is wise to have oil temperature gauges installed in the vehicle. There are also aftermarket products like larger transmission oil pans and differential covers that allow more fluid and oil for increased cooling. And there are covers with cooling fins for more efficient cooling.

While on the topic of oil and fluids, perhaps the most important thing you can do is replace fluids, oil, and filters on a regular basis. Fresh, clean oil contributes to better lubrication and major components running cooler.

I mentioned tow/haul modes when I discussed tow packages. It’s important to understand proper gear selection when towing a trailer, to maximize towing efficiency and minimize stress and strain on the tow vehicle. Review your tow vehicle owner’s manual to properly understand tow/haul modes and gear selection when towing a trailer.

There is more to this topic, but this is a good start. If you would like to learn more about tow vehicles and towing trailers visit RV Online Training


If you value what you learn from, would you please consider becoming a voluntary subscriber by pledging your support? Every contribution, no matter how modest, helps us serve you better. Thank youLearn more here.

Facebook Groups you might like
RVing with Dogs
RV Tech Tips
RV Advice
Towing Behind a Motorhome
RVing Over 70
. . . and the official Facebook page

Winterizing your RV this season? Amazon has a wide choice of RV antifreeze.


0 0 votes
Article Rating
Subscribe to comments
Notify of

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Inline Feedbacks
View all comments
1 year ago

None of it made any sense. I just make sure the vehicle can tow at least 6500 and the trailer is around 3500 or less. I have both and it tows like it is not there. I have a jeep grand cherokee with a 21 foot trailer. Towed great in the mountains of Colorado. Just remember to take it easy thru wolf pass. That took forever to get up that mountain.

Dana D
1 year ago

What’s rarely mentioned is allowing your TV’s engine to warm up before driving. It’s 32 degrees in your garage or driveway. You start your TV, back out into the street, and rapidly accelerate to 50MPH. What do you think is going on inside your engine?

Tommy Molnar
1 year ago

One of the BEST investments I’ve made is to get a Banks iDash gauge. With it I can monitor every sensor in my truck. I can set up five ‘pages’ with different information. Temperatures, tire pressures, percentage of DPF in my exhaust system, how much DEF is remaining, whether I’m REGEN’ing or not, and on and on. I just have the basic iDash gauge, no pedal monster. I love this thing!!sq%3DiDash

Gary Broughton
1 year ago

Had 3, 3/4 ton Ford diesels and put 200,000 on each. Had all fluids changed when required. Took care of all 3 and had a throttle body go out. Changed tires by 70,000 miles and batteries in 2 of them.
Had 3 flats, in all these miles, 2 of these on the trailer. Changed tires on trailers at about 50,000. Changed springs on one trailer, they barely met specks, and for G forces or sideway movement. But had good times.

Bob P
1 year ago

For the most part Mark’s article is good but I would differ on the part about trailer weight. Yes your tow vehicle may tow a trailer that weighs the max trailer weight rating, however I have found in my 42 years of towing if you limit your trailer weight to 85% of the trucks rated capacity you and your truck will be happier and safer. My first experience at pulling a travel trailer was with a trailer that was 475 lbs less than my trucks rating, all because the salesman assured me “yeah your truck can pull that easy”. He was right as long as I was on flat level highway and didn’t go over 55 mph which was the speed limit at the time. The first time we got into hills and curves it became a “white knuckle experience”. Since that time I limit my trailer towing to 85% capacity and never experienced those problems since.

Chic Sanders
1 year ago
Reply to  Bob P

Agreed. Towing a boat/camper at max tow capacity an hour away is okay. Towing a camper for 8 hrs or multi day trips is a completely different situation.

Glen Cowgill
1 year ago

Diesel you need to monitor the Exhaust Gas Temperature (EGT) and Transmission fluid temperature which are gauges that don’t normally come with the truck. This is more especially true when using aftermarket tuners. Learn your tow vehicle.

1 year ago
Reply to  Glen Cowgill

Transmission temp is important to watch in a gas tow vehicle as well. But you are correct a lot of vehicles do not have the extra gauges. Or you have to press buttons to find it deep in the menus. That is why I installed an aftermarket tuner box as it gives you extra gauges even if you don’t change the engine tune.

Subscribe to our newsletter

Every Saturday and Sunday morning. Serving RVers for more than 20 years.