Rv Tech Savvy: Tire Compounds — Revisited

This is in regard to my “Tire Compounds” letter in the June issue. Thank you so much for the information [that different tire types result in different ride characteristics]. Can you offer info on what compound tire I should purchase, maybe in a Goodyear or Michelin tire? Also, would it be OK to run a softer tire up front, with the Dunlops in the rear?

Roger Speigner | Dothan, Alabama

Motorhome tires are expensive, and while I recommend that owners use tires designed specifically for motorhomes to get the best ride and service life, now that you have these tires, I suggest that you keep them for cost reasons. As long as they are properly inflated for the loads (using a load-inflation table), they should provide satisfactory service. Installing motorhome-specific tires to the steer axle may be a reasonable compromise if they really bother you. I want to make it clear that rubber compounds will make little difference in ride quality; they mainly affect traction and wear. Sidewall stiffness is a much more significant variable between motorhome and truck tires. You might find Michelin’s website helpful.


Electric Motorhomes

Considering that Mercedes-Benz is in the process of electrifying its Sprinter (possibly in partnership with Tesla), and the popularity of the chassis, that innovation should be interesting for Class B and C motorhomes. Other manufacturers should soon follow this undeniable trend.

Yvan Jérôme | Laval, Quebec, Canada

As I mentioned in “Electric Vehicles” in the June issue, there are electric or hybrid chassis undergoing development. Of course, major challenges include initial cost, weight and charging during a road trip.


Ignition Switch Failures

We have a 2001 Georgie Boy Suite on a Workhorse chassis that we bought new. Several years ago it wouldn’t crank right after I made a stop on the road. I had to replace the ignition switch that’s down inside the steering column. The same thing happened again recently and I had it replaced again. Last month I was having trouble cranking it and it was bad again. The shop has not determined what is causing it. Can you give me any help?

Don Taylor | Pittsburgh, Pennsylvania

This was a common problem because there is too much current routed through the ignition switch, which will burn the internal contacts, eventually causing switch failure. You’ll need Workhorse part no. W8002085 to make the repair. It’s available from Ultra RV Products. It consists of a kit with relays to reduce current through the switch. This fits 2000-2005 Workhorse chassis.



Towing a 2019 Hyundai Veloster

I bought a 2019 Hyundai Veloster Turbo Ultimate with six-speed manual shift and I’m thinking about flat towing it behind our Leisure Travel Vans Unity 24MB motorhome. My research shows that previous manual-shift Velosters are towable through 2017. I believe Hyundai did not make this model in 2018, but came out with a slightly “redesigned” Veloster for 2019. In talking with Blue Ox and Roadmaster folks last October, they had no idea whether or not the 2019 Veloster would be towable, so they couldn’t comment on availability of baseplates, or even if the previous model baseplate would fit. My Hyundai owner’s manual only describes emergency/temporary towing. My local Hyundai dealer will neither confirm nor deny compatibility for flat towing. Same story from the folks at Hyundai America/California. The dealer, when pressed about warranty issues, said such related repairs would probably be at “dealer discretion.” Any comments?

Robert Fresh | Wichita, Kansas

I always recommend that prospective buyers who intend to dinghy tow verify capability by reading the exact owner’s manual. The 2019 model is not officially approved by Hyundai for flat towing (and is not included in our 2019 Guide to Dinghy Towing for this reason). If a vehicle is factory-approved for dinghy towing and a warrantable failure occurs, which is not due to negligence on the part of the operator, related repairs should not be at dealer discretion. But if it’s not approved for towing, it’s a gray area.


Tire Inflation Tip

We have a 2003 Newmar 40-foot motorhome. The tires are Michelin XZA2 size 295/80R 22.5. The maximum psi is 120. I was told by my tire dealer to put 120 psi in all six tires, but the ride is very hard. My coach’s front axle weight is 11,240 pounds, and the rear is 18,560 pounds. The chassis is a Freightliner XC. What air pressure should I have in my tires?

John Mason | via email

Your tires were designed for all position over-the-road heavy truck use, not motorhome applications. They’re intended to provide long wear and low rolling resistance, but not necessarily a soft ride. However, they are very overinflated, based on the weights you provided. These pressures should be verified when the coach is fully loaded. Michelin provides an online load-inflation table. According to this, for the tire size and weights you provided, you should be able to run 80 psi front and 75 psi rear, which will soften the ride.


Flat Towing a 2012 Chevy Captiva

Have a tech question?

We purchased a used 2012 Chevy Captiva LT V-6 with a six-speed automatic transmission. I installed a baseplate and wired it for flat towing. My problem is with the fuse that needs to be removed when towing so that the battery doesn’t drain. The instructions in the owner’s manual don’t match the actual instrument panel fuse box. I know that this Captiva is a clone of the 2009 Saturn VUE, which I’ve seen being towed behind many motorhomes. So someone out there knows what fuse or fuses need to be removed.

Jerry Scantlan | via email

Yes, the Captiva is nearly identical to the VUE. The information I have indicates “remove the 2-amp IGN SW fuse from the instrument panel fuse block and store it in a safe location.” This should keep the battery from running down, since the IGN needs to be in the ACC position when towing.

If you are still unsure which fuse to disconnect, temporarily remove a battery cable and connect an ammeter between the cable terminal and battery post. Then switch on the ignition and note the amp draw. Remove fuses until the current drops to almost nothing. The fuse that does that is the one that needs to be removed during towing. This works for any vehicle.

For convenience, you might want to install a switch such as the one listed online at Camping World.


 

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