9 Tips for Safely Driving an RV on Steep Grades

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Driving an RV (in particular gassers) can be stressful, especially when navigating steep grades and mountain passes at altitude. During our drive over the Continental Divide on I-90 in Montana, Marc shared some great tips on how he safely navigates our RV up steep grades and back down again, without overheating the brakes. Whether you drive a gas RV, diesel pusher or truck and trailer, you’ll find many of these tips promote good, safe driving practices, while helping reduce wear and tear on your vehicle.

Click the video above to watch and/or simply scroll down to read the 9 tips.

Just east of Butte, Montana while crossing the Continental Divide on I-90, our coach was just down to just 30mph on a 6% grade while driving over the mountain pass. As many of you know, our RV is a 36′ gas motorhome which weighs 22,000 pounds, and as usual, we were towing our Mini Cooper Convertible mounted on a tow dolly weighing about 3,500 pounds – that’s a total weight of 25,500 pounds.

A gas RV has substantially less power than a truck or diesel RV when driving up these passes, so you just have to take it slower. Plus gas coaches don’t have the advanced engine braking or airbrakes of diesel RVs, so you need to take extra care when driving down the mountain. You don’t want to overuse and overheat your brakes, reducing them to mush which makes them virtually unusable and substantially decreases safety. Not to mention the stress and white knuckling that goes along with it!

Here, Marc shares his tips for how to navigate steep grades and mountain passes safely, calmly and arriving with cool brakes.

9 Tips for Driving Your RV on Steep Grades

  1. Be Patient  Accept that you’re going to be driving slow and other drivers will be expecting you to be driving slow, so just be patient.
  2. Use Hazard Lights – Anytime you are driving say 20-30mph below the posted speed limit, turn on your hazard lights to alert other drivers you are going extra slow, as a good safety precaution.
  3. Downshift before Ascending – Before you even start going up the hill, downshift to a lower gear so you have some extra power.
  4. Use Tow Haul Mode – Put your transmission in Tow Haul Mode which uses different gear shifting to keep the engine in a more optimal range (we leave our RV in Tow Haul Mode almost all the time).
  5. Descend Slowly – When preparing to go down the mountain pass, bring your speed way down (even as low as 30mph, depending on the length and steepness of grade of the hill) before you even begin your descent and stay in Tow Haul Mode. This allows you to use more engine braking and gives you room to increase your speed safely. If you start driving down the hill at a high speed and try to come down to a lower speed, it’s going to be a lot harder on your brakes.
  6. Downshift before Descending – If the RV doesn’t automatically downshift itself when going downhill, firmly press the brake to force the transmission to downshift. This will increase your engine speed (and rpm) so the engine will be doing some of the braking for you, minimizing the amount of time you need to use your brakes.
  7. Minimize Braking – When braking, aim to press the pedal for only 15-20 seconds each time and allow time in between so you don’t cook your brakes – the last thing you want is hot, mushy brakes when you need them!
  8. Don’t Overwork it – There’s no sense in working your RV too hard with a screaming engine or overheating brakes. Take it nice and slow and you’ll get better longevity on your vehicle.
  9. Enjoy the Drive – There’s nothing better than the expansive views from the top of a tall hill or mountain, so take your time, relax, enjoy the drive and take in the beautiful scenery!

Remember, RVs are heavy vehicles and you have a lot riding in them, so remember to use caution, be patient and stay safe and slow. If you’re white knuckling it, you’re probably not being safe!

Finally, mountain passes and steep hills are nothing to be afraid of – even in a gas RV. As long as you follow these tips and take your time, you’ll be able reach your destination safely – and who’s in a hurry anyway, right?

PS. We recently discovered the Mountain Directory books, ebooks and apps which provide the locations and descriptions of over 700 mountain passes and steep grades in 22 states. You may also find it an invaluable resource for planning your route to safely navigate and/or avoid mountain passes and steep grades on your travels. 

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23 thoughts on “9 Tips for Safely Driving an RV on Steep Grades”

  1. Alaska, DC, Florida, Hawaii, Illinois, Kansas, Louisiana, Massachusetts, Mississippi, Nevada, New Mexico and Rhode Island you are not allowed to use emergency flashers while driving. All other states you can under hazardous conditions. A rule of thumb for truckers is 15 mph under the speed limit use them to warn other drivers you’re going slow.

    Most RVs are automatics so ascending a grade if you are bouncing between two gears select the lower of the two. Keep an eye on the tachometer and don’t red line the rpms or ride close to it.
    Descending a mountain follow the yellow caution signs. They are there for heavy vehicles to safely descend. Braking, don’t ride the brakes like a car. Let’s say the yellow sign says 35mph. Go down the mountain 35mph. When your RV is trying to go past that slow down to 30 mph and release your brakes, coast to 35mph, brake… Rinse and repeat. Them little gaps of no braking helps keep your brakes cooler. Disc brakes are better about not fading. You just can heat the pads up to they liquify at the point of friction and glaze your rotors. They’ll still work. Drum brakes are the ones that can get you in trouble. The drums can get so hot they expand to the point the shoes barely touch the drums. You might find drums on the rear wheels. Most newer RVs are all disc brakes.

    Lastly, let’s say you did a poor job descending the mountain. You’re at the bottom of the mountain and you smell brakes and see smoke in the mirror. The last thing you want to do is pull over and stop. The heat will build on the wheel and possibly start a tire fire if really hot. Instead keep driving on the flatter ground and let the wind cool your brakes down a mile or so then you can safely stop if you need to.

    Reply
  2. Hi Marc – thanks for the article and advice. New to RV driving and this community. Have a lot paranoia related to mountain driving and brake glazing. We have an 38′ RV converted from a school bus. We’re about 26000lbs, Cummins ISB5.9 with an Allison 4 speed automatic transmission, air brakes, but no jake or exhaust brakes. We’re heading thru AZ later this month and will be driving on I17 to and from Camp Verde up to the Cottonwoods Campgrounds. The Mountain Directory says ‘6% grade for 7 miles”. Suggestions for safe speeds/gear (2nd or 3rd) to maintain for that length of descent with my rig capabilities and any other strategies for navigating these and future downhills?

    Any advice will be greatly appreciated. Thanks in advance.

    -Anand

    Reply
    • Hi there – just replied before seeing your post here – glad to see you have the Mountain directory! You are definitely doing a great job of planning with your resources… Try it with 2nd gear and see how that goes…good to take it nice and easy. Consider disconnecting your toad if you have one. Cheers and enjoy your stay! It’s a beautiful area.

      Reply
  3. BOB while driving my 25 yr old class a in AZ going to Payson on 87 n found 6 & 7% grade. going downhill i had to use 1 low gear all the way with my flashers on took forever but me & my 25 yr old rv made it safe.

    Reply
    • This is the perfect comment for me. We just bought an older used motorhome and our planing our first trip from the West Valley AZ up to Payson AZ and I’m paranoid! We are motorhome newbies and I’m scared to death. I know your post is a few years old but I hope you see this to respond. Which way did you take? We are thinking the 17 up through Camp Verde and back down has less curves.
      Thanks

      Reply
      • Hi Stacy, Sorry for the delay in responding, it got missed. Yes, interstates often have fewer sharp curves and calmer grades than secondary roads since they are primary truck routes. Just take it nice and slow and you will be in good shape. Consider buying mountain directories so you have detailed information on the routes. We love ours. http://bit.ly/MountainDirectories

        Reply
        • Hi Marc – this article and the replies are very helpful. Similar question to Stacy’s and alot of the same paranoia since I’m a newbie to RV driving. We have an RV converted from a school bus. We’re about 26000lbs, 4 speed, air brakes, but no jake or exhaust brakes. We’re heading thru AZ later this month and considering I17 to and from Camp Verde up to the Cottonwoods Campgrounds. The Mountain Directory says ‘6% grade for 7 miles”. Do you have suggestions for safe speeds to maintain for that length of descent with my rig?

          Reply
      • Hi Stacy – got any advice from driving thru Camp Verde related to the downhill descent? We’ll be doing that same drive later in Dec. Thanks. -Anand

        Reply
        • Hi this is Julie at RVLove – we recommend the Mountain Directory West edition – that drive on 17 was actually the reason Rick (the author) wrote the book, as it’s such a long incline. https://mountaindirectory.com – an excellent resource for route planning!

          Start the hill with a really low speed and maintain with your gears. The hill is longer than you think. Take it nice and easy and if you are a motorhome towing, you could consider disconnecting and having your passenger drive it separately, if you think it would be a struggle for your motorhome.

          Reply
  4. Careful giving advice to use hazard lights while driving. In some states it’s illegal to drive while using hazard lights. Those are meant for disabled vehicles.

    Reply
  5. Hi Mark, I have the same engine as you but a different transmission. I don’t have tow mode. Do you wonder about overwinding the transmission on the way down a hill? I have used lower gears gong down but the engine makes a racket and is running close to 5K rpms. Do these engines have a governor that won’t let them destroy themselves? Thanks, I enjoy your videos ~ Steve

    Reply
  6. This was a great article and video, and it couldn’t have come at a more fitting time for me, as lately I have grown to have a huge fear of mountain passes (I have a 40′ fifth wheel, towed by a Ford F550–you saw the matching combo in Asheville). I know about and do follow your advice, but I’m still scared. I think one thing that concerns me is that a number of people have told us that in addition to downshifting and not using the brakes, to watch the rpms. I do watch and I note that it goes into the 4000 range. You are saying this is normal and expected, so that is very reassuring. But the question is how long should it stay revving at that level? A few seconds and try to get it back to the normal (2500) range, or until the top or bottom of the pass?

    I also notice that if I go into 3rd gear, it doesn’t seem to make much of a difference, but if I go into 2nd or 1st, it revs really high. What is the advice here?

    Thanks,

    Reply
    • as a retired transport driver of 30 plus years, your article is very informative for those people towing. you have made good points on the downgrades of the passes and downshifting of the transmission. an old rule used to be if you go up in third you you go down in the same gear, this way if at all you will use minimal braking, especially with the newer exhaust brakes in vehicles.

      have safe travels everyone

      Reply
  7. Our set is a 35 ft type A diesel pusher (13 ton GVW) towing a full size Silverado pickup (approximately 5,600 lbs). We have completed several trancontinental trips over the last 3 years which include Wolf Creek pass and multiple trips on I-70 across the continent divide. We have found that, while we can negotiate these significant passes hooked up we have found it much easier (on driver and equipment) to disconnect the toad. We have a set of walkie-talkies that allows us to communicate easily.

    Reply
    • Yes Cliff, we absolutely agree and have been doing that now – always for passes over 7500′ and sometimes for others, we assess on a case by case basis. Much less stressful, safer and easier on the equipment. And really, minimal inconvenience – you can’t put a price on peace of mind and safety when it comes to driving mountain passes with a big beast of an RV! Thanks for sharing! Especially having a DP, it goes to show this is good practice for many RVers, not just us gas drivers.

      Reply

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