360david Posted February 21, 2018 Share Posted February 21, 2018 Having Just purchased a new Swift Escape 674 I cannot find anywhere in the the mine of information given to me regarding tyre pressures. I did find somewhere on the internet that suggested 80psi. This seems very high to me. Can anyone suggest a reasonable PSI that would be suitable for my motorhome and give me a comfortable ride without being to firm. many thanks David Link to comment Share on other sites More sharing options...
Don636 Posted February 21, 2018 Share Posted February 21, 2018 You need to take your motorhome to a weighbridge to find out the individual axle weights when fully loaded then search online for a chart from the tyre manufacturer which will give you the appropriate tyre pressures for your specific tyres and loads. Link to comment Share on other sites More sharing options...
Solomongrundy Posted February 21, 2018 Share Posted February 21, 2018 As said by Don, take it to a weighbridge (typically around £5) with it in fully laden 'holiday' mode and get each axle weighed. Then you can find the tyre pressures required for the tyres you have fitted - and whether you're overloaded or not. B-) B-) B-) B-) Link to comment Share on other sites More sharing options...
360david Posted February 21, 2018 Author Share Posted February 21, 2018 Many thanks for the Advice. There is a weighbridge fairly near me so will get on to it asap David Link to comment Share on other sites More sharing options...
graham Posted February 21, 2018 Share Posted February 21, 2018 Don't forget that if your van is fitted with TPMS (which it almost certainly is) then you probably will not be able to lower the pressure from the factory setting (just less than 80 psi) without setting off the low pressure warning system. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted February 22, 2018 Share Posted February 22, 2018 A Swift Escape 674 is built on a Fiat Ducato chassis and - to the best of my knowledge - no motorhome manufacturer is choosing to specify Fiat’s optional TPMS system (though UK manufacturers building motorhomes on a Peugeot Boxer chassis generally seem to include TPMS within their models’ standard specification). An Escape 674’s Fiat-recommended front and rear tyre pressures will be 5.0bar and 5.5bar (15” wheels) or 5.5bar and 5.5bar (16” wheels). Those pressures will be given in the Fiat Ducato Owner Handbook and Swift will not advise differently. Even if a motorhome owner weighs the vehicle and seeks a recommendation from the manufacturer of the tyres, that recommendation will not override the Fiat-recommended pressures, so choosing pressures that differ from the Fiat-recommended pressures will always remain the motorhome owner’s responsibility. An Escape 674 will have Continental or Michelin ‘camping-car’ tyres. Continental will advise on tyre pressures based on weighbridge measurements (the relevant Continental data are also available on-line) but Michelin will specify that 5.5bar be used for a motorhome’s rear-axle ‘camping-car’ tyres irrespective of weighbridge-measured rear-axle load figures. Link to comment Share on other sites More sharing options...
Solomongrundy Posted February 22, 2018 Share Posted February 22, 2018 It has been alleged that Michelin are in partnership with Fixodent Denture Adhesive - you'll certainly need a good supply of the glue if you have false teeth and you keep the pressures at 5 / 5.5 bar. The first MH we had had Michelin tyres fitted and after one long journey with the tyres at the high recommended pressures I dropped them considerably to Continentals recommended pressures - and had a much smoother ride and a long tyre life without any problems. (lol) (lol) (lol) (lol) Link to comment Share on other sites More sharing options...
Derek Uzzell Posted February 22, 2018 Share Posted February 22, 2018 As has been said several times before on this forum Michelin has merely been following the advice of the ETRTO (European Tyre and Rim Technical Organisation) about operating “CP”-marked tyres on a motorhome’s rear axle at a pressure of 5.5bar (80psi). If Michelin tyres fitted to a motorhome are not “CP”-marked, Michelin will be prepared to offer pressure-to-axle-weight advice for both front and rear axles of the vehicle. But if a motorhome’s Michelin tyres are “CP”-marked, Michelin will advise 5.5bar for the rear axle irrespective of a measured rear-axle load being provided by the vehicle’s owner. Michelin will, however, advise a potentially lower pressure for “CP”-marked tyres fitted to a motorhome’s front axle. Continental takes a less rigid attitude to providing pressure-to-axle-weight advice for their “CP”-marked tyres, but it’s the ETRTO that’s the driving force behind Michelin’s stance. Link to comment Share on other sites More sharing options...
graham Posted February 22, 2018 Share Posted February 22, 2018 I thought TPMS was compulsory on vehicles registered after Nov 2014 or does that only apply to cars and not PLG vehicles. Link to comment Share on other sites More sharing options...
ron. Posted February 22, 2018 Share Posted February 22, 2018 Derek Uzzell - 2018-02-22 6:40 PM As has been said several times before on this forum Michelin has merely been following the advice of the ETRTO (European Tyre and Rim Technical Organisation) about operating “CP”-marked tyres on a motorhome’s rear axle at a pressure of 5.5bar (80psi). If Michelin tyres fitted to a motorhome are not “CP”-marked, Michelin will be prepared to offer pressure-to-axle-weight advice for both front and rear axles of the vehicle. But if a motorhome’s Michelin tyres are “CP”-marked, Michelin will advise 5.5bar for the rear axle irrespective of a measured rear-axle load being provided by the vehicle’s owner. Michelin will, however, advise a potentially lower pressure for “CP”-marked tyres fitted to a motorhome’s front axle. Continental takes a less rigid attitude to providing pressure-to-axle-weight advice for their “CP”-marked tyres, but it’s the ETRTO that’s the driving force behind Michelin’s stance. It might help the original poster if it was explained that the ETRTO reason for sticking to a pressure of 80psi for CP tyres is to act as a safeguard against the number of motorhome owners who overload their rear axle - it is not the optimum pressure. For those that know their axle loadings the pressures can be vastly different. A case in point was my previous PVC on a Fiat maxi chassis which when loaded was front heavy by some 100kg. This didn't stop ETRTO recommending that I should put 25psi more pressure in the more lightly loaded rear tyres than the front! Link to comment Share on other sites More sharing options...
Derek Uzzell Posted February 23, 2018 Share Posted February 23, 2018 The history behind the advice to use high inflation-pressures for ‘camping-car’ tyres fitted to motorhomes (and particularly to the tyres fitted to the rear axle(s)) has been regularly discussed on this forum. Tyre manufacturers who are ETRTO members are listed here https://www.etrto.org/Members/Current-Members/Tyres-Full-Members Michelin produces a “Safety and utilisation advice” tyre guidance document https://www.michelin.co.uk/content/pdf/TC_Safety_Guide_UK.pdf This includes the following text. "Motorhomes require tyres are that are adapted to their conditions of use. In 2003, the ETRTO (European Tyre and Rim Technical Organisation) changed the standard, as well as its recommendations relating to motorhome tyres, and now says "CP-type tyres have been designed to cater for the higher loads imposed by motor-caravans”, and that "it is strongly recommended that motorcaravans are only fitted with CP-tyres”. At replacement, Michelin strongly recommends the fitting of CP tyres to vehicles originally homologated and fitted with CP tyres. The load on the tyre must not exceed its maximum limit for any reason, i.e. the load rating must be respected. The ETRTO also states that where CP tyres are used on the rear axle (single fitment), they must be inflated to a pressure of 5.5 bar instead of the normal pressure of 4.75 bar for example. MICHELIN CP marked tyres are therefore specially designed to be driven at an inflation pressure of 5.5 bar (550 kPa) This higher pressure improves road holding and increases resistance to the challenging driving and usage conditions encountered by motorhomes, especially with regard to loads (occasional static and/or dynamic overload associated with this type of vehicle; considerable rear overhang, load imbalance, high centre of gravity due to highly positioned loads) and long-term periods of disuse.” It will be noted that Michelin says "The ETRTO also states that where CP tyres are used on the rear axle (single fitment), they MUST be inflated to a pressure of 5.5 bar...”, not “...they SHOULD be inflated to a pressure of 5.5 bar...”. The ETRTO produces tyre-related standards and one might expect ETRTO members to adhere to those standards. There’s no leeway in the ETRTO’s dictat about using a 5.5bar inflation-pressure for CP-marked tyres fitted to a motorhome’s rear axle (It’s MUST not SHOULD) and if Michelin is asked for advice, that’s the advice they will give. So, if David’s Swift Escape 674 has Michelin “Agilis Camping” tyres and he weighs his motorhome, tells Michelin which tyres the 674 has, gives them the measured axle weights and asks what tyre pressures would be appropriate, Michelin will tell him “5.5bar/80psi for the rear tyres”. It’s also worth adding that, if a tyre manufacturer’s representative is asked for inflation-pressure advice for, say, a Swift Escape 674, the chances of that representative being aware of the motorhome’s dimensions (height, rear overhang, etc.) will be nil. The ETRTO sets standards and does not recommend what indiividual owners of vehicles should do. A motorhome owner can weigh his/her fully-loaded vehicle to obtain axle loadings, consult the manufacturer of the vehicle’s tyres and inflate the tyres to the pressure that he/she is told will be appropriate. The tyre manufacturer’s recommendation will be based on data obtained during testing and should produce a combination of safety and comfort. Whether the result is ‘optimum’ in areas like cornering, road-holding, stability and general ‘feel’ is another matter though. Personally, I don’t want to have my vehicles’ tyres inflated unnecessarily hard, but as I prefer a firm ride to a sloppy one I’ll err on the high side when deciding what pressures to use. My Rapido 640Fmotorhome has Michelin “Agilis Camping” 215/70 R15CP tyres and I know Michelin would tell me to use 5.5bar pressure for the rear tyres - so there’s little point me asking Michelin for advice. Driving the Rapido initially with front and rear pressures of respectively 5.0bar and 5.5bar resulted in a harsh ride and steering that I found over-light, so I’ve reduced the pressures to 4.5bar and 5.0bar. The ride is still firm but not harsh and the steering has a bit more ‘weight’. Whether the 4.5bar/5.0bar pressures are optimum would depend on how one defined ‘optimum’, but they suit me. Link to comment Share on other sites More sharing options...
Brock Posted February 23, 2018 Share Posted February 23, 2018 Thanks for the guide, Derek. Makes interesting end enlightening reading. I had semi air suspension fitted to the rear axle and the ride is fine at 5.5bar. It was awful when just relying on the Alko rear suspension. My tyre pressure on the front, based on advice from Michelin for my axle loading, is 3.65 to 4bar [the former is 'empty', the latter when fully loaded]; Hymer say 4.25bar for the front. TyreSafe, the independent advisory body, now recommends 5.5bar for my rear tyres - it didn't use to do. Perhaps it is the suspension that should be questioned not the tyres. Given the choice, I'd prefer at least semi air suspension rather than a silver paint job. According to the latest MMM, the Style Pack and Leather interior options cost £5,790; chuck in a few bob more and you could be in full air suspension territory. Link to comment Share on other sites More sharing options...
monique.hubrechtsgm Posted February 23, 2018 Share Posted February 23, 2018 An al-ko on the rear has independent rear suspension, together whit the front struts Alko ACs gives a better ride than fiat standards. that is proven by test records on paper. I do not believe in semi AIr, but full air on a alko chassis. Not on a fiat chassis. About tyre pressures follow the axle loads, or look at your tyre, if it is not flat. Link to comment Share on other sites More sharing options...
747 Posted February 23, 2018 Share Posted February 23, 2018 This is a guide to Motorhome tyre pressures from the Tyresafe website and works out fine for my Tag axle van. A normal 4 wheel setup seems to always give a pressure of 80 psi (5.5 Bar) on the rear axle. Try it and see how it works out for yourselves. https://www.tyresafe.org/check-your-pressures/motorhomes/ Link to comment Share on other sites More sharing options...
Keithl Posted February 23, 2018 Share Posted February 23, 2018 747 - 2018-02-23 7:52 PM This is a guide to Motorhome tyre pressures from the Tyresafe website and works out fine for my Tag axle van. A normal 4 wheel setup seems to always give a pressure of 80 psi (5.5 Bar) on the rear axle. Try it and see how it works out for yourselves. https://www.tyresafe.org/check-your-pressures/motorhomes/ And as a comparison here is the TyreSafe brochure from 2008... If you compare 215/70 R 15 CP 109 with axle loads of 1,854 kg Front and Rear the new website gives pressures of Front 68 psi 4.69 bar Rear 80 psi 5.5 bar Whereas the old brochure gives Front 60 psi 4.16 bar Rear 70 psi 4.82 bar So recommended pressures have risen in the last ten years! Keith. Edit to add: Just spotted the Note (1) against Single Rear that states "Driven Wheels Only". So for a FWD Ducato the lower figure applies to BOTH Front AND Rear tyres! Link to comment Share on other sites More sharing options...
Derek Uzzell Posted February 24, 2018 Share Posted February 24, 2018 In the early 2000s, when the only ‘motorhome’ tyre being marketed was Michelin’s “XC Camping” range, Michelin’s Van Tyre Technical Data UK guide footnoted XC Camping tyres “For maximum load conditions when used on mainland Europe it is recommended that the rear tyres are inflated to a pressure of 80psi”. There was confusion at one stage over whether 80psi should only be used on a ‘driven’ rear axle (Why?) and now there’s this ETRTO ‘command’ that relates to motorhomes with tandem rear axles as well as single rear axles. Link to comment Share on other sites More sharing options...
747 Posted February 24, 2018 Share Posted February 24, 2018 I have just fitted 4 new 16" tyres to the 2 Tag axles on my van. The axles are rated at a Max load of 1500 Kg and the normal pressure I use is 50 PSI (cold) which will be around 55 PSI when warmed up. I fitted Michelin Agilis tyres but they are not the 'Camping' variant, just Commercial tyres with the same Load rating. I have Michelin Agilis Camping on the front axle (pressurised to 65 PSI cold) and if my spare is a Michelin Agilis Camping, then I am covered in the event of a puncture. The main difference between Camping and Commercial is that the Commercial are not M & S rated but that is of no consequence because they are not on driven axles and I don't tour Europe. Link to comment Share on other sites More sharing options...
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