Having looked at all the interesting comments on this subject I think Lutz may have a significant point over tyres and the lateral support they give when towing. I tow with a Vectra Estate which has the option of larger wheels and low profile tyres fitted (this tows brillantly). I had cause to borrow a friends Vectra Estate with the normal wheels and tyres to tow my van. This combination was certainly not as stable as my own car. Lorries passing made the van much more twitchy. The ride both towing and solo is much harder on the lower profile set up but certainly seems more stable.
James, curious about your comments regarding wheel sizes, I have a vectra estate 51 plate 2.2 dti diesel fitted with 195/65 r15
tyres, its the most stable car i have towed with.
Royston
I must say stability is no problem to me despite towing a twenty foot twin axle van with a 2 Ltr Laguna estate. I used to tow the van with a Renault 25. The outfit is at top of the max gross train weight or 100% tow limit for those not so used to the dept of transport chatter.
All I use is a cheap and cheerful snakemaster stabiliser, but probably the best device I have is my wind deflector. This is a throw back to the 70's, one you used to see on most car roofs because we towed bricks on wheels in those days.
It has a sculptured whale tail type shape and has been converted by me to fitt the roof bars on the car. Because of it's shape wind gets deflected up and over the caravan so speed and fuel economy are upto 15% better. But more over, wind also gets dispersed to the sides which I believe (sorry no wind tunnel tests to prove, but I am a qualified prototype tester)cosset's the side of the caravan which aid's stability.
As pointed out by others tyre pressures also play their part. Even a 5 Psi difference in tyre pressure can upset any vehicle's handling.
My stability cost me less than
All I use is a cheap and cheerful snakemaster stabiliser, but probably the best device I have is my wind deflector. This is a throw back to the 70's, one you used to see on most car roofs because we towed bricks on wheels in those days.
It has a sculptured whale tail type shape and has been converted by me to fitt the roof bars on the car. Because of it's shape wind gets deflected up and over the caravan so speed and fuel economy are upto 15% better. But more over, wind also gets dispersed to the sides which I believe (sorry no wind tunnel tests to prove, but I am a qualified prototype tester)cosset's the side of the caravan which aid's stability.
As pointed out by others tyre pressures also play their part. Even a 5 Psi difference in tyre pressure can upset any vehicle's handling.
My stability cost me less than
Hello Steve,
an intersting disitaion, two points though, improved fule consuption by 15%, that seem a lot, but if its true well done.
The second point relates to your down hill "free wheeling" or coasting, where you claim the caravan is pushing the car. Whilst there is a change in the dynamics of an outfit under these conditions, I find it very hard to believe the caravan is actually pushing unless you are using engine braking or are catually applying the brakes. Perhaps you can clarify.
an intersting disitaion, two points though, improved fule consuption by 15%, that seem a lot, but if its true well done.
The second point relates to your down hill "free wheeling" or coasting, where you claim the caravan is pushing the car. Whilst there is a change in the dynamics of an outfit under these conditions, I find it very hard to believe the caravan is actually pushing unless you are using engine braking or are catually applying the brakes. Perhaps you can clarify.
Yes I do get a 15% increase in fuel economy. I get 24mpg without the deflector and close to 28mpg with the deflector, the car does 41.5mpg average solo.
As for the other incident I didn't go too deep into the detail, but I actually had to accelerate rapidly upto 70mph plus to avoid the crash that was happening next to us because someone was rear ending another car. We were going down hill at the time and when I felt the van swaying I decelerated which then ment the van caught up on the over run coupling and was pushing the car. Due to the weight match (100% tow capacity) I had " the tail wagging the dog".
Hope thats explained the situation.
We tow a lexon EB with a SWB Fronterra and find it to be a very stable outfit. However that has not always been the case. it took a bit of trial and error with loading when we first bought the van (our last van was a mercury which is about 5ft shorter). I have moved the spare wheel to a carrier just to the rear of the axle, adjusted the nose weight to 98kg. All heavy items TV etc over the axle and as already mentioned it is very stable. I use a Bulldog 200Q blade stabilser. Mention has been made of the M5 , I have noticed that just South of Bridgwater vans are prone to some swing as the landscape is flat and unprotected from the elements also there are some ruts in this part of the road. I have noticed this for many years with several different tow car caravan outfits.
You say that the caravan was becoming unstable because it was pushing the car. However, it could not have been pushing very hard because if it did, the brakes on the caravan would have been applied and then the outfit would have become stable again. Applying the footbrake enough to deploy the caravan's brakes as well is a recognised means of catching an unstable outfit.
Alex,we had a fleetwood some years ago that did the same we finally rectified it by doing something they advise you not to do,put extra weight in the tail end and we towed on french toll roads at 75mph.results straight and true.
dont give up find a way round it,good luck
Don't get me wrong I also think the vectra estate is an excellent stable tow car. It was just a small observation that my vectra with its low profile tyres seemed slightly more stable than a vectra estate with standard tyres. Both Vectra's were on a 54 plate although my model had a slightly higher kerb wt. which may have accounted for the slightly more stable ride rather than the tyres.
I also assume that by inflating tyres to that recommended in the handbooks for high loads can also make the lateral flexing of the tyres less.
DON'T TRY THIS AT HOME. Quite a few years ago I used to tow a caravan with a transit van for use when working away from home.
Without any thought for loading nose weights etc the caravan a Compass Omega, was dragged all round the country as fast as the transit could pull it, I won't mention speeds here sufice to say that going down hill we could get up quite a lick!.
Eventually a family came along and I decided to clean up and resurect the Compass for cheap family holidays as I didn't require it for work any longer. The first few outings were with a Ford Galaxy tow car and in consideration of the family speeds were reduced, but I have to admit not by much. Again no stability at all occured.
I then bought a brand new Dicovery 2 and of course thought this would just be the same as the transit & Galaxy - WRONG . The first time out going down the first hill that we came to on the M1 the outfit got into what can only be described as a terifying snake, we were in the middle lane at just under 70MPH and the situation took all three lanes to bring under control, I was left in a cold sweat and needless to say the family were left very upset.
Having thought about it I think it was most likely due to a combination of the Discovery's long rear overhang ( in comparison to the other two) and the air supsension. I would suspect a Discovery with Active Cornering Enhancement would be more stable due to less body roll.
Imediatly after the incident I bought a brand new Swift Conqueror (twin wheel) which tows very well to the legal limit, I did have a "moment" with it once when due to inattention going down hill the speed had crept up and a very large box van passed very close and very fast.
I now set the cruise contol to 60 and sit back!
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