I tow a 2012 Honda Fit, used to tow a 2001 Ford Ranger (5-speed). Within our camping club other towed vehicles have included Cobalt and HHR (essentially the same GM compact platform), Olds Alero (GMX130 platform), and second generation Chevy Tracker (Suzuki Vitara platform).
Various Saturn models, GM compacts and mid-size sedans, GM compact SUVs, Ford compact and mid-size SUVs, and Honda CR-V have been popular as towed vehicles. Some people tow full-size 4x4 pickups and SUVs.
The reason for a lot of towable cars from GM was use of the 4T40E transmission in compact and mid-size cars; this one lubricated itself while towing, as did an earlier 3-speed automatic made for the first generation Saturn. Honda's 4-speed automatic from that era was derivative, although Honda further developed it. Honda used variations of this transmission everything from the Civic and Element on up to the minivan, and larger SUVs, including also the Acura brand, and at one time all Hondas were treated as towable. After a class-action settlement having to do with transmission life expectations, Honda decided to say CR-V only, then added the Fit from its second year here.
When Ford introduced the Edge SUV, they made a point of designing the automatic transmission to be towable, and the same transmission has since been used in other models, particularly SUVs. But because Ford has used several different automatic transmissions in that era, one can't blanket a broad product line as towable as you can with 1995-2010 GM compacts and mid-size sedans.
There are quite a few manual transmission subcompacts, and a few manual transmission compact cars, that are towable four down but you won't see many of them because hardly anyone in this country will drive a manual transmission car, and few people much under the age of 60 have ever learned how.
Because of recent changes in transmission technology to reach ever higher CAFE goals, there are not nearly as many cars today towable four-down as there were from the late 1990s up until 2010.
Type of vehicle should be what meets your transportation needs. Which make or model of the type should be one that you can tow four-down. I think it should be a used car of moderate age and mileage, because your motorhome will be throwing road trash at it.
Tom Test
Itasca Spirit 29B
