Is a 40' RV too long for much of MX?

You will have to hit the tope at an angle; otherwise you will drag your hydraulic lifts.

You might find doing that 5000 times a day a bit tiring, especially when there is usually a vendor standing in the middle of each tope. Just slow right down to whatever speed your suspension demands and you won't have clearance problems. Misjudge your speed too much and you won't have any suspension left. Actually the really bad topes are those that are laid diagonally across the road. Just have a look at all the cars with only 4" clearance under their sills who seem to manage OK.

More danger is the several inches sudden-death drop off right at the edge of the tar on many country roads - even some of the toll roads.

You also have to watch things like the steep side street drop offs in some towns like Villa Corona. (hopefully they have fixed that Pemex ramp everyone uses this year)

Topes (speed bumps) are one of the problems with all vehicles, but moreso with the big rigs that don't have adjustable height air suspension. You will have to hit the tope at an angle; otherwise you will drag your hydraulic lifts.

Whatever size you like will be fine in most cases. You'll probably have less stress with a shorter length, but if you're a good driver and don't hit the detour with the sudden downhill that might high-centre you, it should be do-able. If you have air susp, it would be good to have a "max height" switch available. The other thing to consider is the weather, much different than at home. Under normal circumstances, you will spend a lot less time inside than out - we find the patio or whatever passes for one to be the most-used room we have ! RYV

No matter what model and size RV you purchase, practize making tight turns in confined spaces so that you are comfortable using both mirrors and being able to complete the turns.

Take a set of walkie talkie radios to comunicate with a partner for guidance, and always look up, there could be a tree branch or a low power cable, and when you park next to the curbs make shure that you are well away from tearing the awning off the RV with a utility pole that is to close to the road, remember that streets have a curve to guide water to the curbs and the rv leans into the sidewalks.

When in doubt, get out and walk or drive to see what lies ahead, if you go to smaller cities like Guanajuato or Tasco, do not go in to town with the rig, take the toad or a Taxi, streets are to narrow and twisty + Guanajuato has narrow tunels on some streets.

If you follow the big rigs and or the passerger buses you are OK, its a diferent matter when you do not see them going down the same street that you are on, also try to hug the center of small streets, trees might not stick out that far. Yust remember that most of the towns where built when no cars where arround, horse and buggies yes, ergo narrow streets and tight turns.

Otherwise have a good time.

navegator

You just have to know where you are going. If you have a toad, use it to check a route our through small unfamiliar towns first to avoid gettign trapped in tight streets or dead ends. Look for overhead hazards, like signs or balconies sticking out to far, trees & low wires.

And don't try going down into Santa Maria del Oro crater with one.

One good trick is to follow buses through a town

We have been roaming all over MX in a 40 footer for the past 7 winters. Yes, things can get tight. Read the Church book. Plan your route. We use Microsoft Streets & Trips 2013 to plan our route to make sure we do not find ourselves in the middle of small towns. We tow a Honda CR-V for the sight seeing trips. We have been to many places they say we cannot go with a 40' and have survived. How experienced are you with the size? Note that fuel in MX may not be OK for post 2006 diesel engines. Use Google Earth to look at campgrounds you might stay in. Have a GPS that does not rely on internet as you may not be able to get internet in many areas. Keep in mind that when planning you may not be able to go as fast or make as many miles as in the US - we do not ever drive at night in MX due to topes, cows, horses, etc. (Topes are called speed bumps in the US and are everywhere in MX and cannot be seen at night). If you cannot find a large enough campground when you look in the Church book you can ask here if anyone knows of a Pemex station or other place to stay - ask people to be specific with things like Latitude and Longitude as some directions given here can be next to useless. Many here have blogs in their signatures - read lots of blogs.

We drove all of mexico from west to east some years ago in a 36ft and had no real bad issues. We have a 40ft now and drive down close to Puerto Vallarta for past 4 years and have not had any problems at all. If your going to full time rv in and around Mexico, the 36ft would be better if you plan on a LOT of traveling in Mexico. One issue to consider possibly is to have a tow dolly instead of the normal tow hitch.... The normal tow hitch will allow only very limited back up, where tow dolly, I assume, will allow great back up lengths. This might come in useful in some tight spots. Might consider an older model as low sulfer diesel is hard if not impossible to find in Mexico.

A 40 footer is not unusual in mexico, usually with a toad. For practice, drive Route 6 for a few states. Sort of like that but in Spanish. That would be for the libre (free) roads, auto pistas are toll roads like the interstate highways.
Follow along with Church's book or disconnect the toad to do a first inspection before heading down a narrow street.

We haven't had any problems in Our Rig ,it's 38 Feet! We are far from the longest rig, there are lots that are 45 feet, and those ones do look a bit tight!