Road Tests

[wabbit]

Since most of the dealers for the models in which I'm interested are a few hundred miles away, I'm trying to put together a game plan to maximize the time spent evaluating the vehicle.

It is a given that we like trips that involve twisty mountain roads, so I'll try to fit something like that into the schedule. I also like to have the salesman drive for awhile, while I stand up in the back, and rock back and forth, to get a feel for wind and weight transfers through the twisties. Accelerating onto a highway is a given.

What am I forgetting, that I should be adding onto my list?

[Mike]

Brake shimmy after continuous usage on long downhill grades, and excess engine rpms to climb them.
Some vans have brake heating issues and can actually warp rotors under continuous application on long
downhill grades. Would also be an opportunity to test transmission hold to assist in downhill braking.
When climbing check the tach and see how fast you're going uphill, and how high the engine is revving,
Good to know how much of a struggle it would be to climb steep uphills, and you will probably encounter
both of these situations eventually.
Also, keep in mind added cargo for traveling and full tanks (gas, propane, fresh water, gray/black) will
add extra weight, and will exacerbate any negative performance issues you might notice.

Turning radius might be good to know, in case you get into a situation where it might be problematic.
Wheelbase will usually kill your ability to turn tight corners or hairpins. Some vans are just a bit too long for some roadways, and will be prohibited like the larger class C and class A rigs, so that might be a problem if you plan to drive on any. Going to the Sun road in Glacier NP has restrictions. I'm sure others do too.

Some Sprinters have engine brakes which is a nice feature. Steve from Guelph mentioned his PW has
them and I believe Davydd's GWV does, too. Saves constantly replacing your running shoes, if you have to constantly drag one foot to help you slow down on steep downhills. (sorry, Chev chassis humor )

Too bad you can't get one up onto I-80 in the Sidney, NB to Des Moines, IA stretch, or down to I-40 east of Kingman, AZ on a "breezy" day. You'd really get to feel the sway and effect of crosswinds on these beasts. Some say it's subjective, and I tend to agree. I find those 2 stretches of road nasty on certain days with a southerly crosswind (usually in the early Fall), but some folks think it's not that bad.

That's all I can think of for mountain driving. We've done a lot of it too, and it can be challenging in any vehicle, not just an RV, depending on the road, wind, traffic, visibility, weather. We came through the mountains in Colorado on I-70 in September from 90F temps in Arizona last year to snowfall at elevation just west of Denver.

[wabbit]

Originally Posted by Mike

That's all I can think of for mountain driving. We've done a lot of it too, and it can be challenging in any vehicle, not just an RV, depending on the road, wind, traffic, visibility, weather. We came through the mountains in Colorado on I-70 in September from 90F temps in Arizona last year to snowfall at elevation just west of Denver.

Good points! Our previous class-B was a Coachmen on a Ford frame with the long overhang. They made the horrible decision to build it on a 24500 frame, which was far too light for the very high center of balance for the vehicle. The sway and vulnerability to the slightest breeze made it a read handful to drive.

Where we live, there are twisty mountain passes to get to almost any other part of the country during winter. Ideally, I'd want to slap some chains on it for a quick test during those conditions, but I can live without that right now. Center of gravity, cornering on the twisties, and brakes/acceleration onto highways can tell a lot.

The brake shimmy is something I should ask current and former owners, since I doubt that any dealer is going to give me they type of road test I really want to do. That's what weekend rentals are for.

[Mike]

Brake shimmy/warped rotors. There have been discussions on here somewhere about that topic.
Try searching on rotors or warp or something and it should find the threads.

[markopolo]

Might be worth knowing the cold tire pressure before the test.
An empty van with max tire psi with ride rough.
Under-inflated tires with also cause "handling" problems.
I don't think I'd do the rock back and forth while in motion you mentioned. That's just me.

[Mike]

In a high center of gravity van, I would agree. Trying to rock the thing side to side might be possible,
but not really worth much.
In a lower center of gravity van it's probably safer to do it, but I can't see much benefit there either.
If the issue is how much of a "sail" the vehicle is in a cross wind, you really have to get the tire pressures right, as you suggested, and fill the tanks up, as if you were traveling, and get into a cross wind somewhere.
Then see how it feels.
At least that's what I'd do.