Since opening Horton Common in 2014 I’ve seen hundreds of caravans turn up on-site, both single and twin axle variants. Furthermore, we have owned a caravan in our family pretty much all my life. When I’m having conversations with our guests about their new or upcoming caravan purchase the topic of single vs twin axle caravans sometimes pops up. I’ll sometimes be asked which I think is best. However, from my own observations and the feedback I’ve received from our guests, there is no outright winner between the two. Both single axle and twin axle caravans have their pros and cons. Therefore with this post, I’m going to discuss the different advantages and disadvantages. You will then be able to use that knowledge to help guide your next caravan purchase.
In terms of our own family caravan, we currently own a first-generation Alu-Tech Bailey Pegasus 514. Its a single axle caravan with a rear washroom and a length of 6.48m. Hence, its a very long single axle caravan which has certain implications and I’ll be referencing those later. However, please note this post is not intended to be a critique or endorsement of any particular brand/model of caravan. The content below on single vs twin axles are general comments which are applicable to all makes and models of touring caravan sold in the UK.
Introduction to the Single Axle vs Twin Axle Caravan Debate
It would be remiss of me to not quickly describe the difference between single and twin (double) axle caravans, so here it goes. With a single axle caravan, you have one axle and therefore two wheels. With a twin/double axle caravan you have four wheels. To generalise, single axle caravans are commonly smaller/lighter in weight, where twin axle caravans are typically longer/heavier. With that being the case, if you read the below and believe that a twin axle is your prefered option please note they are generally heavier and longer caravans. Therefore, you need to ask yourself certain questions.
Can You and Your Car Actually Tow a Heavy Twin Axle Caravan?
Is your car actually capable, technically and legally to tow a heavy twin axle caravan? First off, you obviously need to check the official tow rating for your vehicle. This will be in the owners manual, but with a quick check online it will also come up. Secondly, there are other factors to consider with towing a longer/heavier twin axle caravan. For instance, factors such as torque/power output of your tow car, its MPG and traction from the drive system all need to be considered. I’ve got two posts with my thoughts on the best cars to tow a caravan and the 2WD vs 4WD debate you may also want to read.
Furthermore, as I discuss in my post on caravan weights if you passed your driving test after 1997 unless you have passed the additional B+E test its unlikely you can legally tow a heavy twin axle caravan. I wanted to bring up these points first and foremost. Because I want you to be aware of the circumstances when you may not be able to technically or legally tow a twin axle caravan even if you want and can afford one. Ok, I’ll now get into discussing the actual pros and cons between single vs twin axle caravans.
Towing Stability – Single vs Twin Axle, Is There Much of a Difference?
A question which our guests have brought up the past and I see in the various caravanning forums are the questions over stability. In other words, are twin axle caravans more stable to tow than single axle caravans? Based on my own observations with our long single axle caravan and the comments/feedback from our guests, the answer is it depends. For instance, with our long single axle caravan in some instances, it does suffer from pitching/bobbing during towing.
What is Trailer Pitching?
What is pitching? Well, its when the front of the caravan moves up and down during towing. This can pull and push on the cars tow bar. Now, we have reduced the number of incidences of pitching while towing over the years with loading our caravan in different ways. However, part of the issue is due to the length of the caravan being on a single axle. Hence, the axle is the pivot point upon which the seesaw action during pitching occurs. If the caravan was a twin axle I do believe that pitching would be less likely. Why? Well, with a twin axle there would be a wider pivot point, hence it would be harder for the caravan to pitch up and down during towing.
Resistance to Air Turbulence/Snaking While Towing
Ok, say you are driving down the motorway. You’re on the inside lane towing the caravan and you get overtaken by a lorry. In some instances, quite a bit of air turbulence can be generated where the air bounces off the side of the lorry and pushes into the side of your caravan. This sideways force on the caravan can potentially cause instability. The caravan may start to pivot side to side on the axle or maybe even move side to side on the road itself, also commonly known as ‘snaking‘. Well again, with a twin axle caravan you have a larger point contact with the road. So all other factors being equal, typically a twin axle caravan will provide more resistance to these instability issues compared to a single axle caravan.
The Weight of Your Tow Car
Now, reading my comments above it may appear that twin axle caravans always provide more stable towing performance. As a general rule, I believe that is true. However, there is also a lot of other variables at play. For instance, the weight of your tow car is a very important factor. You may have heard of the 85% ‘rule’ with regards to the tow car/caravan weight relationship. In other words, you want to the laden weight of the caravan to be 85% of the cars kerb weight. However, it is also generally acknowledged that more experience caravanners can safely tow a 100% match.
The general point being, for stable towing you don’t want the caravan to be heavier than the car. Otherwise, during adverse towing conditions the tail (caravan) might start wagging the dog (tow car). Well, as stated above twin axle caravans are generally heavier than single axle caravans. Hence, even though twin-axle caravans have a larger pivot point in contact with the road to help with resistance against pitching and snaking that additional weight may be a problem. In other words, if you are going to choose a heavy twin axle caravan, you want a tow car with sufficient weight match.
Modern Tow Cars and Caravan Stability Systems
My above comments on the difference in towing stability between single and twin axle caravan are really all about physics. In other words, the weights of objects, pivot points, friction etc. However, we now need to consider electronics and computers. For instance, in my post on caravan stabilisers, I discuss the AL-KO ATC system. The ATC system electronically assists the caravan brakes to increase caravan stability while towing.
Servicing your caravan stabiliser hitch to keep the friction pads in a good condition is very important for any single or twin axle caravan: Image – Amazon
More modern cars now have various electronic stability control systems. Some of them specifically designed to assist with towing. We are quite a few years away from an autonomous electric tow car which will drive its self. However, over the coming years more of these electronic towing stability, systems will be introduced. The takeaway point is that modern tow cars with a modern caravan can really help to bridge the divide between the inherent towing stability differences between single and twin axle caravans. Where in many cases, there may be very little difference in towing stability between certain single and twin axle caravans.
Caravan Tyre Cost/Blowouts – Twin Axle Pros and Cons
Caravan tyre safety is something I’ve discussed a lot in my previous posts. As caravan tyres carry a lot of weight, they are inflated to a higher pressure than car tyres. Furthermore, caravan tyres often spend a lot of time sat idle which creates issues with flat spots. That’s why I think caravan tyre pressure monitoring is a very good idea, and so do caravan insurance companies. In reference to this specific post on single vs twin axle caravans where do caravan tyre blowouts come in?
Whether you are considering a single or twin axle caravan I would definitely encourage you to consider a tyre pressure monitoring system: Image – Amazon
Well, with a twin axle caravan you obviously have two wheels on either side of the caravan, not just one. Now, if a nail in the road caused the tyre blowout potentially both tyres on the same side could fail. However, if only one of the tyres fails you have a better chance of keeping the caravan under control compared to a single axle caravan. With a twin axle caravan and a tyre pressure monitoring system you will have a better chance of avoiding a potentially very nasty accident.
However, with caravans, you should be changing your tyres every 5 years, no matter the remaining tread depth. Hence, with a twin-axle caravan, you will be spending double the amount on tyres as you would with a single axle caravan. Therefore, with a twin-axle caravan, they not only generally cost more to purchase in the first place, but their upkeep costs are also higher due to the additional tyres.
Caravan Layouts – Single vs Twin Axle Caravans
In my post on caravan layouts, I discuss that a popular option today appears to be the transverse island bed with rear washroom. Due to the nature of this layout, it will typically be found on longer caravans more suited to a twin axle chassis. However, there are single axle caravans with this layout. You can get pretty much get any layout on both single and twin axle caravans. However, with a twin axle version, you will generally have a bit more space to move around etc.
Another variable at play though is the growing selection of 8 foot wide caravans. Hence, where someone may have opted for a longer caravan to get more space, they may now choose to opt for a wider caravan instead. Now, there is quite a heated debate in the UK caravanning community on how suitable 8 foot wide caravans are for UK roads. However, you could also make the same argument with regards to very large twin axle caravans. My point is that the introduction of more 8-foot wide single axle caravans means you may not have to opt for a twin axle to get the space you want.
Caravan Payloads and Motor Movers
The above may seem like a bit of odd title, but all will become clear. With a twin axle caravan, you will generally find they have a higher payload capacity. How much more additional weight you can load into a twin axle caravan over a single axle obviously varies from model to model. However, its fair to say as a general rule with a twin axle caravan you will be able to carry additional belongings. However, in some instances that additional payload capacity can be wiped out if you want to install motor movers.
Its important to note that motor moves have to be deducted from a caravans payload capacity: Image – Amazon
As a general rule, its harder to turn a twin axle caravan over a single axle caravan. It goes back to my previous comments on pivot points. While for towing that wider pivot point on a twin axle provides more stable towing performance, its a hindrance when it comes to manoeuvrability. Now many caravanners today choose to have a motor mover fitted. Its just simply so much easier to steer your caravan with a remote control than trying to reverse a caravan. But with a twin axle caravan can you get away with a single motor mover on each side or do you need a mover for each wheel?
Well, I’ve spoken to a couple of guests over the years about this. From those who have a twin axle caravan and one mover per side to those with a mover per wheel. Its a pretty clear consensus, for a twin axle caravan for the movers to work properly you need a mover for each wheel. But what that also means is additional weight eating into that additional payload capacity. Hence, with a twin axle caravan with four motor movers, you may not have the additional payload capacity remaining that you expected.
On the topic of manoeuvrability, it is worth noting that some caravan sites that don’t have a road and hardstanding like ourselves here at Horton Common actually ban twin axle caravans. Why? Well, the second axle on a tight turn drags. Hence, if the caravan site is just grass a twin axle caravan can tear at the surface and churn up the grass. Just something you should be aware of.
Conclusions on Single vs Twin Axle Caravans
So my above comments are not intended to put you off single axle or twin axle caravans. My comments are simply to make you aware that each has its own inherent advantages and disadvantages. You can then consider the points above when looking at your next caravan to determine if a single axle caravan or twin axle caravan will be better for your specific circumstances. For instance, if you don’t intend to change your tow car you need to thoroughly consider its capabilities. How heavy is your tow car? Is it powerful enough to tow a heavier twin-axle? etc.
Thanks for reading, I hope you did find my comments above on single vs twin axle caravans useful/informative. I also hope in the near future you consider coming to visit us here at Horton Common caravan site. 🙂