tow cars

[Steve L]

We have bought a 1997 Renault Laguna 2 Ltr RT estate which we are having a spot of bother in trying to decide what it's maximum manufacturers tow limit is. I understand about Gross train weight, MTLM etc but the hand book with the car gives weights for Driver only and fully loaded car etc. My previous car (Renault 25) was simple it had a stated tow limit of 1300kgs braked. Why oh why can't the manufacturer's just state the obvious. Just what the tow capacity realy is. Or do they just want to see what the Police work it out to first when they are booking us for over loading. Has anyone else had simlar experience?

 

[Lutz]

The criteria which determine maximum towloads are very varied, ranging from engine power, engine cooling, braking and/or clutch performance to vehicle dynamic performance, vehicle structural limitations and market (i.e. road) conditions. Some of these criteria are more dependent on the total weight of the car/caravan outfit than that of just the caravan. In such a case, it would suggest that the lighter the car, the heavier the caravan can be but that, again, is in direct contradiction with the safety aspect (the 85% recommendation, for example). As a result, there must be a trade-off between 2 conflicting issues, requiring in some cases complicated compromises on the part of the car manufacturers in order to satisfy market demands for maximum possible towloads. This has resulted in the need for differentiated solutions. For some models, for example, GM Europe specifies different max. towloads for trailers under 1.40m height or trailers with low moments of inertia (horseboxes and the suchlike).

 

[ProfJohnL]

Hello Steve, I quite agree the method of working out what a car can or can't tow is complicated, but there is logic to it. A car manufacture has to consider safety, performance and legalities when specifying towing capacities. All cars will be given a gross train weight which must not be exceeded. This is usually less than the combined gross car weight and permitted gross trailer quoted weights. So this means you can have a fully laden car, but you must keep the trailer weight down to stay within the Gross train weight. Some combinations of car and caravan will not be legal simply because the unladen weight of the caravan causes the outfit to be greater than the car manufactures limits. If in doubt always assume the worst case or use a public weigh bridge to confirm the real figures for your outfit.

 

[ProfJohnL]

Hello Steve, I quite agree the method of working out what a car can or can't tow is complicated, but there is logic to it. A car manufacture has to consider safety, performance and legalities when specifying towing capacities. All cars will be given a gross train weight which must not be exceeded. This is usually less than the combined gross car weight and permitted gross trailer quoted weights. So this means you can have a fully laden car, but you must keep the trailer weight down to stay within the Gross train weight. Some combinations of car and caravan will not be legal simply because the unladen weight of the caravan causes the outfit to be greater than the car manufactures limits. If in doubt always assume the worst case or use a public weigh bridge to confirm the real figures for your outfit.