garyhumphreys said:
I am definitely going to buy an insignia hatchback for towing my caravan but not sure if the 140ps engine has enough power to pull a 1435kg van. Can anyone help?
GARY
Hello Gary,
The short and simple answer is YES the 140ps Insignia will to the 1435Kg caravan. The more complex answer is will it meet your expectations or will it just meet your needs?
Which ever car and engine you go for, you cannot escape the fact that by virtually doubling the weight of the solo car you are going to notice a considerable drop off in performance. Is that going to be a problem? In real life the majority of cars have capabilities which vastly exceed the limitations of traffic movement, and in practice we rarely utilise the full potential of the car. So by adding the caravan, will it still be able keep up?
In the not so distant past most cars used petrol rather than diesel. It is usually the case that petrol engines develop most of their torque and power at towards the top of their rev range, so to make sure there was enough torque to get a car and caravan moving the industry came up with the suggestion of 40bhp per ton of total weight. However the game changer has been rise of the diesel cars.
Diesel was the king in terms of practical fuel economy, but also they had an inherent characteristic which made them very popular with the haulage industry. Torque at low engine speeds. If you were to look at the specifications of LGV and HGV you will see that a diesel with only 310bhp is being used to move 44 tonnes That gives only 7bhp per tonne! In fairness some units go up to 500bhp which is still only 11bhp per tonne.
To get the same performance in an HGV using pertrol engines I suspect you would be looking towards the 1000 to 1500bhp, simply because of the difference in torque characteristics.
So with the industries suggestion of 40bhp per ton based on petrol engines, it is perfectly reasonable to look for a lower bhp when considering diesels, and especially when its a turbo diesel which further enhances the torque at low rpm. My estimation is that you will get perfectly acceptable ( I.e not being so slow as to hold traffic up) performance with a TD of 30 to 35bhp per tonne. Anything more is a bonus but is probably not going to improve journey times which are more often than not dictated by other traffic of speed limits.