Rapido Tyre Pressures

[stevec176]

Have been checking my tyre pressures and have got confused so wondered what others have their pressures set at. When I bought the van I was told 5bar (72.5psi) front, 5.5bar (79.5psi) rear but checking on tyre safe it gives 3.5bar(51psi) front and 4.2bar (61psi) rear so I'd like to know what others have their vans set to please.

My axle weights are 1600 / 1900, tyres are VancoCamper 215/75 R16C 116/114R and the max pressure on the tyre is 75psi.

[Robinhood]

Unlike Michelin, Continental will supply by email, and with quoted tyres and axle loads, recommended pressures that vary from the 5bar/5.5bar maxima generally quoted. (and they are often quite a bit lower).

 

They also publish a data book with pressure "tables" in them, by tyre and axle load.

 

The latest version I can find for download is here:

 

https://blobs.continental-tires.com/www8/servlet/blob/376746/e0854f2c7866c64da551474b998ef8b3/download-technical-databook-data.pdf

 

and has the table for your tyres on pages 84/85.

 

By my reading, that would give pressures of 3bar and 3.75bar for your axle loads, though, when I've referenced these tables, I've generally applied a 10-15% uplift margin, which would put you in the area of the Tyresafe values you quote..

 

If you're confident about your axle weights, and want a definitive answer, why not ask them:

 

https://www.continental-tyres.co.uk/car/about-us/contact-us/contact-technical

[stevec176]

Thanks for the info, the axle weights are reasonably accurate, give or take a few kilos having had the van weighed twice and both times similar weights.

I'll drop Continental an email to see what they say.

Thanks

[Derek Uzzell]

Have your tyres been replaced?

 

I believe your Rapido 665f was new in 2016 and originally had a maximum overall weight of 3500kg. I know that (in 2017) you were considering having the vehicle’s overall weight ‘uprated’, but I think you eventually decided not to.

 

For a Rapido built on a Ducato ‘light’ (3500kg) chassis, the original equipment tyres should normally be ‘camping-car’ type (Continental VancoCamper or Michelin Agilis Camping) with a specification of 215/70 R15CP if the wheels are 15” diameter or 225/75 R16CP if the wheels are 16” diameter.

 

For 215/70 R15CP tyres the Ducato Owner Handbook advises pressures of 5.0bar(front) and 5.5bar (rear) and, for 225/75 R16CP tyres, 5.5bar (front and rear). In both cases, on a lightly loaded motorhome, the result would be a very harsh ride.

 

The tyres on my 2015 Rapido 640F are 215/70 R15CP Michelin Agilis Camping and I choose to use 4.5bar(front) and 5.0bar (rear). This still results in a ‘firm’ ride, but that’s fine by me.

 

I suggest that, whatever Continental tells you would be ’safe’, you err on the high side. If your tyres are actually 225/75 R16CP, I’d be tempted to go for 4.0bar(front) and 4.5bar (rear) and see what that feels like.

 

 

[ColinM50]

Had my motorhome's annual habi service last week and asked the dealer what tyre pressures to set them at. He said all m/h's are the same; 5 bar front 5.5 rear

[stevec176]

Hi Derek, you remember well, I was considering the upgrade but didnt in the end. When I bought the van I had 16" alloys fitted hence the 215/75 16C. I've been using 5 & 5.5bar since but last year I purchased a TPMS and when in Spain the pressures were getting upto 95psi which got a bit worrying so this year I've lowered them down to 3.5 & 4.2 bar. With such a big difference I thought I'd like to know what others were doing.

[BruceM]

ColinM50 - 2020-03-01 2:51 PM

 

Had my motorhome's annual habi service last week and asked the dealer what tyre pressures to set them at. He said all m/h's are the same; 5 bar front 5.5 rear

 

Which I guess goes to show that your dealer is a poor source of motorhome tyre pressure advice. For my Dethleffs for example, the manufacturer recommends my 16” tyres to be 4.5 bar front and rear. I actually run at 4.6 bar which once warmed up on a drive in the summer climbs up to about 5 bar.

[Keithl]

stevec176 - 2020-03-01 3:06 PM

 

...With such a big difference I thought I'd like to know what others were doing.

 

I am also running at the figures obtained from the Conti-Online book calculated for my axle loads.

 

That is 48 psi (3.3 Bar) Front and 60 psi (4.1 Bar) Rear for my 225/70 R15 Conti Vanco's.

 

Keith.

[Derek Uzzell]

stevec176 - 2020-03-01 3:06 PM

 

Hi Derek, you remember well, I was considering the upgrade but didnt in the end. When I bought the van I had 16" alloys fitted hence the 215/75 16C. I've been using 5 & 5.5bar since but last year I purchased a TPMS and when in Spain the pressures were getting upto 95psi which got a bit worrying so this year I've lowered them down to 3.5 & 4.2 bar. With such a big difference I thought I'd like to know what others were doing.

 

OK - that would explain it.

 

Continental’s “VancoCamper” tyre was supeseded a few years ago by “VanContactCamper”, but the data in Continental’s 2015-2016 Technical Databook for VancoCamper are as Robinhood has said earlier, with pressures of 3.0bar and 3.75bar quoted for axle-loads of 1600kg(front) and 1900kg(rear).

 

The 116 Load Index equates to a maximum axle-loading of 2500kg for a ’single wheel’ axle, but Continental’s data indicate that - when used on the rear axle - the pressure for a 2500kg axle-loading can be 5.25bar, 5.5bar, 5.75bar or 6.0bar. (I vaguely recall Continental suggesting that, if a motorhome were being operated with its rear-axle loaded to 2500kg, it would be good practice to use 6.0bar.)

 

A 215/75 R16CP motorhome tyre inflated to a 5.0bar or 5.5bar ‘cold’ pressure may easily reach 95psi when the vehicle is being driven in hot weather. What you really need to watch out for is if similarly high pressures are being reached when you are using 3.5bar and 4.2bar.

[bolero boy]

stevec176 - 2020-03-01 1:02 PM

 

Have been checking my tyre pressures and have got confused so wondered what others have their pressures set at. When I bought the van I was told 5bar (72.5psi) front, 5.5bar (79.5psi) rear but checking on tyre safe it gives 3.5bar(51psi) front and 4.2bar (61psi) rear so I'd like to know what others have their vans set to please.

My axle weights are 1600 / 1900, tyres are VancoCamper 215/75 R16C 116/114R and the max pressure on the tyre is 75psi.

 

Steve here is a section from the Continental email response to me re: pressures....you'll see i have very similar axle weights to yourself and the same 16" Vanco Campers...although mine are 225 width.

 

Based on the following:

 

ContiVanco Camper 225/75 R16 (CP*) 116 R tyres.

Front Axle: 1600 Kg - 3.0 bar/ 43.5 psi (max weight for pressure given = 1730 kg)

Rear Axle: 1820 Kg - 3.75 bar/ 54.3 psi (max weight for pressure given = 1840 kg)

[Derek Uzzell]

If 2020 model-year Ducatos have a ‘fixed settings’ TPMS as standard, that’s likely to be the end of motorcaravanners downwards adjusting tyre pressures to match pressures to axle-loadings.

[stevec176]

I emailed Continental Tyres and received the reply below. I'm trying to attach the table too but it wont allow me to copy it so will upload it soonest.

 

Thank you for your email and I completely understand your concern.

 

It is extremely likely that the relevant information supplied with the chassis is documented for use as a commercial vehicle, therefore proposed before the conversion to a motor home. For this reason, Continental tyres would always recommend having the motor home weighed on a weigh bridge at your heaviest travelling weight, including liquids to achieve specific axle weights. In some cases, the coach builder will also put their recommended pressures on the vehicle plate. However, the majority put this to the maximum inflation pressure of the tyre to cover all loads being applied and not specific loads which often, are not near the plated weight you actually travel at.

 

The volume and pressure of the inflation medium is what carries the load and if it is not sufficient then the tyre can suffer damage, hence why it is extremely important for the correct loads to be obtained, in order to inflate the tyre correctly.

 

Experience shows that due to the weight distribution of vehicles in the leisure industry such as motor homes the likelihood of overloading or uneven weight distribution tends to put a greater load on the rear axle rather than on the front axles, where the weight tends to remain more consistent. It is true that when braking occurs the weight transference is to the front, but this only tends to be for short periods, whereas overloading on the rear axle can be present over long periods, when the tyres are rotating at high speed.

 

 

This is the main reason that with CP Camper type tyres the inflation pressures at the rear is deliberately set higher. Although this also has a bearing on the contact area when negotiating grassy parking areas and also to the sidewall deflection, which influences the body roll.

 

The 69 psi written on the side of the tyre is for the Northern American market only and the inflation pressure of the tyre can exceed this value within its safety operating range.

 

I have included the chart for these specific tyres to help with pressure vs. load.

 

(*CP- Camper) (Single fitment (S) = two wheels per axle, Twinned fitment (T) = four (or more) wheels per axle)

 

 

 

 

 

 

[Robinhood]

Derek Uzzell - 2020-03-02 8:59 AM

 

If 2020 model-year Ducatos have a ‘fixed settings’ TPMS as standard, that’s likely to be the end of motorcaravanners downwards adjusting tyre pressures to match pressures to axle-loadings.

 

...or it might see an increase in drivers investing in MultiECUscan in order to adjust the otherwise fixed settings.....

 

;-)

[slowdriver]

stevec176 - 2020-03-01 3:06 PM

 

........I've been using 5 & 5.5bar since but last year I purchased a TPMS and when in Spain the pressures were getting upto 95psi which got a bit worrying so this year I've lowered them down to 3.5 & 4.2 bar.

So simple question, will the in-built TPMS system on my 2020 Ducato detect over as well as under-inflated tyres.?

 

Many thanks

[slowdriver]

I think I have discovered then answer to my question in the Fiat Manual after a closer examination of the small print.

 

"The system only warns that the tyre pressure is low: it is not able to inflate them."

 

I wasn't expecting the TPMS to inflate the tyre (!)

But I also concluded that it does not alert you to pressures above the recommended maximum.

 

[Steve928]

Indeed, the X290's system adheres to the bare mininum specified by the UN document R141e and the referenced ECE regulation.. Google will find you a copy to read if you want to better understand its workings.

[Steve928]

By the way, my lockdown Christmas project is a Raspberry Pi based system to decode the 433Mhz TPMS transmissions using a SDR (Software Defined Radio) dongle. Will be able to monitor pressures, temperature, battery state,time of last transmission etc. direct from the wheel sensors on a smartphone.

Just for fun whilst not being able to properly use the van but it's already proved very informative (and useful, identifying a dying sensor battery that neither Multiecuscan or AlfaOBD could identify and which the system itself just reported as its ever-helpful 'tyre pressure monitoring unavailable').

 

 

 

[Derek Uzzell]

These earlier TPMS-related forum discussions may be of interest

 

https://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/Tyre-Pressure-/56208/

 

https://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/TPMS-Elddis-Envy-120-2018/49595/

 

https://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/X290-tyre-pressure-reset-/40276/#M532466

 

https://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/More-TPMS-fun-games/43610/

 

In the past complaints from motorhome owners about being unable to appreciably reduce tyre pressures (to improve ride quality) usually related to Peugeot Boxer-based models - which normally meant motorhomes produced by UK converters like Bailey and Auto-Sleepers. But if - as I suggested above in March - new Fiat Ducato-based motorhomes are now being equipped as standard with the same TPMS system as used on Boxers, there’s likely to be a lot of grumbling about this.

 

I notice that a device is marketed which (apparently) can wirelessly disable the Fiat/Peugeot type of TPMS system.

 

https://tpmsbypass.com/product/fiat-eu-tpms-bypass/

 

Assuming the device works safely, this should allow reduced tyre pressures to be used without the TPMS system producing an alarm. The other side of the coin, of course, is that the TPMS system would be inoperative.

[Keithl]

Derek Uzzell - 2020-12-23 2:18 PM

I notice that a device is marketed which (apparently) can wirelessly disable the Fiat/Peugeot type of TPMS system.

 

https://tpmsbypass.com/product/fiat-eu-tpms-bypass/

 

Assuming the device works safely, this should allow reduced tyre pressures to be used without the TPMS system producing an alarm. The other side of the coin, of course, is that the TPMS system would be inoperative.

I believe fitting this device will count as a modification to the vehicle which must be notified to your insurance company as you are disabling a safety feature.

 

What would your insurance company say if you had a blow-out which then caused an accident? Your insurance company would ask 'why did your TPMS not alert you to the danger'? Answer... Insurance void!

 

My view for what it's worth,

Keith.

[Steve928]

The TPMS bypass box works by emulating the TPMS transmitters (i.e. the in-wheel sensors) and transmitting its own data bursts either in their place or concurrently using its own sensor IDs. As it is 12v powered and not restricted to miserly coin cell battery use it can transmit both stronger and more frequent signals which are received by the TPMS module and decoded and accepted as the 4 (or 6 presumably) active sensors on the vehicle. It can transmit maximum pressure values that ensure that no alarm is ever triggered.

 

For those that want to disable their TPMS I think that purchasing either Multiecuscan or AlfaOBD and associated hardware would be the better and only slightly more expensive option

 

[Robinhood]

Steve928 - 2020-12-23 5:11 PM

For those that want to disable their TPMS I think that purchasing either Multiecuscan or AlfaOBD and associated hardware would be the better and only slightly more expensive option

....with the added advantage of being able to check/fix/adjust so much more (and always assuming one already possesses a device capable of running the software).

[niktam]

ColinM50 - 2020-03-01 2:51 PM

 

Had my motorhome's annual habi service last week and asked the dealer what tyre pressures to set them at. He said all m/h's are the same; 5 bar front 5.5 rear

I have the same MH and I'm trying 50 front and 60 rear which is a far better ride and you could go lower from what I have seen numbers. However, there are only two of us on board not six!

[Derek Uzzell]

Nicholas

 

This forum thread started on 1 March 2020, discussed tyre pressures for a 2016 Rapido 665f motorhome and ‘lasted’ 2 days.

 

It was mentioned that an aftermarket TPMS had been fitted to the Rapido 665f in 2019 and Chris (slowdriver) revived the thread yesterday asking about the operating principles of the Fiat TPMS factory-fitted to his 2020 La Strada Avanti.

 

Comments elswhere about Elddis Autoquest 196 motorhomes suggest that this model may have been marketed with a Peugeot factory-fitted TPMS as part of its standard specification.

 

https://www.caravanclub.co.uk/club-together/discussions/information-technical-tips-advice/motorhomes/elddis-autoquest-196-tyre-pressure/

 

If the advised tyre pressures for an Autoquest 196 are 5 bar (72.5psi) and 5.5bar (80psi) for the front and rear tyres respectively (which is what I’d anticipate would be the case) and your motorhome has the Peugeot TPMS, I would have thought that lowering those pressures by 22.5psi (front tyres) and 20psi (rear tyres) would almost certainly provoke TPMS alarms.

 

(In fact, based on your posting of 10 December 2020 6:28 PM on this earlier thread

 

https://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/Oil-Change/57008/#M674014

 

it appears thatb your Autoquest DOES have the Peugeot TPMS.)

 

[niktam]

Derek you are correct on all points with the TPMS I was going to see if my Peugeot garage would reset the TPMS on the main service?

My car which comes with the job has the facility where you reset the TPMS from the main screen to whatever you like. I also found out can also lock the car from miles away (with my phone) when my wife leaves the car unlocked with the key in it!

Merry Christmas and thanks for all your effort -greatly appreciated.

 

N

[Derek Uzzell]

There’s plenty of on-line discussion about the Peugeot Boxer TPMS, including having the pressure criteria altered by a Peugeot dealership.

 

https://tinyurl.com/y99mjeey

 

The general situation in late-2018 was summarised here

 

https://forums.practicalcaravan.com/threads/resetting-tyre-pressure-monitor-system.60197/

 

However, the posting of Mon Oct 17, 2016 4:42 pm by “Cymro” in this Auto-Sleeper Motorhome Owners Forum thread

 

https://www.autosleeper-ownersforum.com/t18796-broadway-tyre-pressures

 

may be of particular interest as it mentions a Peugeot dealership resetting the TPMS for £39. The posting includes the following statement

 

"The Peugeot Homologation and External Relations team have advised that 'The tyre pressures that the customer wishes to have (provided they have authorisation from the tyre manufacturer) can be recorded into the TPMS ECU. To do this the vehicle will need to go to an authorised repairer who has access to the diagnostic tool.”

 

If you plan to use 50ps(Front) and 60psi(Rear) pressures, the TPMS thresholds will need to be substantially lower - say 40psi(F) and 50psi®. Otherwise you’ll get TPMS warnings when the tyre pressures reduce naturally in cold weather.

 

Elddis’s technical specification for a 2021 Autoquest 196 indicates that 215/70 R15CP tyres are fitted as standard and the motorhome’s length is 7.34 metres. My Rapido is 6.49m long, has the same tyre specification, has a quoted Mass in Running Order 137kg less than an Autoquest 196, and I use tyre pressures of 65psi(F) and 72psi®. This does result in a firm ride, but noticeably less harsh than the 72psi(F) and 80psi® advised by Rapido (and Elddis).

 

I assume you’ve obtained the 50/60 pressures from Continental Tyres based on weighbridge figures for your motorhome’s front and rear axle loadings (as Michelin will just quote 80psi for CP-marked tyres on the rear axle). But even if 50/60 pressures may be considered ’safe’, you are likely to lose handling precision.