Michelin camping tyre alternatives?

[Guest Derek Uzzell]

In my final response to Norma's "Tyres" posting of 22/01/2005 I said I intended to ask Michelin about the benefits of using their XC Camping pattern tyre rather than an 'ordinary' light-commercial vehicle 10/12-ply rated alternative. This was the content of my e-mail to Michelin: "In the past you have explained to me that your XC Camping pattern tyre, although 8-ply rated, essentially has the load-carrying capability of a 10-ply rated tyre and this unstated additional capacity provides a valuable 'safety margin' for those motorcaravanners unwise enough to overload their vehicles. Looking at the XC Camping data in your technical handbook, I note that this pattern is marketed in sizes most commonly used by motorhomes. Now, I can appreciate that XC Camping can provide potential advantages in those sizes where no 10-ply rated patterns are available (eg,.215/70 R 15 C). However, where an appropriate size 'genuine' 10-ply rated pattern can be obtained (eg. Agilis 101 215/75 R 16 C), is there actually any benefit in choosing XC Camping instead?" I received the following reply: "The use of '10 ply' would give a similar safety-factor, regarding axle weights, as implied with Michelin tread pattern XC Camping. Unfortunately, the '10 ply' mentioned is no longer listed as being available. The useable axle weights would still be limited by the vehicle 'plated' axle values. Best option may be to ensure/verify that the actual weight carried is below each 'plated' axle value, by use of a weigh-bridge, which then allows use of '8 ply' to carry the 'legal' loads." OK - Let's expand on that a little. Whatever sort of motorhome you own, it will normally carry a VIN-plate indicating the vehicle's maximum permitted axle loads and it's these weight restrictions that will define what tyres are suitable for it. However, same-size tyres can have a significantly different load-carrying capacity dependent on their design/construction. The tyre industry tends to talk about "ply rating" to describe a tyre's load-carrying capability. Ply-rating goes back to cross-ply tyre days and does not relate directly to the number of 'plies' (ie. layers of material) involved in a modern radial tyre's construction. Nevertheless, it's a convenient shorthand for comparing one tyre's 'strength' with another, with the higher the ply-rating figure (eg. 6-ply, 8-ply, 10-ply etc.) the greater a tyre's load-bearing capacity. To the best of my knowledge, if you own a motorhome with 15" diameter wheels, the highest ply-rated tyre you can obtain is 8-ply. However, if your motorhome is SEVEL-based (Citroen/Fiat/Peugeot), there is a strong likelihood it will have been fitted from new with a 'Camping Package' that included Michelin's XC Camping tyres. As I said in my message to Michelin, XC Camping is 8-ply rated (and marked as such on the tyre side-wall) but has been designed to have equivalent load-bearing performance to a 10-ply rated tyre. This design feature provides potential benefits when a motorhome is driven habitually near (or beyond!) it's VIN-plated maximum permitted axle-loads. So, when it comes to tyre replacement time and your 'van already carries 15" XC Camping Tyres, if you weigh your motorhome in fully loaded state and find its axle loads are significantly below its VIN-plate figures, you can confidently choose an 'ordinary' 8-ply light-commercial vehicle tyre instead (eg. Agilis 81). But, if your 'van's weigh-bridge axle-load readings approach the VIN-plate maxima, you might be well advised to stay with XC Camping tyres. Motorhomes (and I'm really referring to Euro-built designs here) with 16" diameter wheels are another matter as you can obtain suitable-size tyres in 8-ply, 10-ply or XC Camping patterns. The most popular 16" tyre size on more recent motorcaravans will be 215/75 R16C as fitted to the wheels of SEVEL-based 'vans using the 'Maxi' standard or Al-ko chassis and, once again, the tyres originally fitted will probably be XC Camping. Now, at replacement time, you can do as described above and take the 8-ply route (if your van's axle-loads are well within the permitted limits) or you can choose to stay with XC Camping. But the third option is to opt for a 10-ply rated tyre. Michelin advises that 215/75 R16C size is no longer available in their Agilis 101 range, but 10-ply rated tyres in this size are available from other manufacturers. A bit of casual Internet trawling showed that, unlike Michelin where the ply-rating is normally apparent from the tyre name (eg. Agilis 41, 51, 61, 81 or 101), other tyre manufacturers' products are less transparent in this respect. Thus same-size tyres may be sold in different ply-rating versions but share the same name (Continental's Vanco tyre - which came out well in ProMobil's test - is an instance of this). This is something to watch out for. It also seemed that the cost differential between same-size 8-ply and 10-ply rated tyres from the same manufacturer was often not large. Previous postings and press comments have mentioned the high cost of XC Camping tyres and sporadic supply problems. It would seem from the above that (at least for 16" tyres) an ordinary 10-ply rated light-commercial vehicle tyre will provide 'heavy load' motorcaravanners with a genuine alternative to XC Camping and offer possibly better road performance, cost savings and availability. 'Camping' tyres are now being produced by Pirelli and, I believe, other manufacturers have also expressed an interest in this specialist market. However, I've not researched what sizes are being marketed, what the ply-ratings are, or what the costs and availability are.

[Guest Alf W]

As a result of recent posting on this matter, and a fright when I saw the inside wall of my rear o/s tyre at MOT inspection, I have been pursing this. My Autosleeper Executive (1997) has 195/70/15 tyres. Neither Michelin or Pirelli do camping tyres in this size. Vanco 81's are available but not 101's. As a result I have gone for Michelin Agelis 81's. I hope I've done the right thing ? Rear Axle weight is 1750Kg and total MAM 3200Kg.

[Guest Mike Chapman]

Hello Alf, The Michelin Agilis 81 in 195/70R15C has a load index of 104R which gives a MAXIMUM axle load of 1800 kgs and a MAXIMUM vehicle weight of 3600 kgs, suitable for your vehicle. The Conti Vanco 81's would also have been suitable. All comes down to price in the end. Regards, Mike Chapman.

[Guest Brian Ramsden]

Replying to Alf W, I have a 1996 Talisman with a chassis upgraded to 3500Kg MAM and a rear axle load of 1900Kg. I have changed the tyres to Agilis 205/70 R15, which have a maximum load of 950Kg. These are shown in the vehicle handbook as fitted on certain versions of the Boxer, and they fit on the existing rims. The rim size they require is 5½-6½, compared with 195/70 of 5-6. the slight increase in "rolling circumference" of 2.3% is within the allowable limits for MOT purposes. If my memory serves me correctly the 195/70 R15 have a maximum load of 900kgs, so you get a useful additional load margin.

[Guest Mike Chapman]

Hello Derek, Thanks for the info from Michelin, I was not aware that they had dropped the Agilis 101. Did they indicate that they would be producing a replacement or uprating the Agilis 81? Ply rating is important but the Load Index is the key to vehicle weight/loading. The maximum weight now for the 16 inch Agilis is an axle load of 2640 kgs for a single wheel axle and 4240 for a twin wheel axle. (Load Index 118/116 on 225/75R16). For 15 inch Agilis this is 2240 and 4240 kgs (Load Index 112/110 for Agilis and XC Camping, 225/70R15). There seems to be some doubt as to whether the 225/70 R 15 XC Camping is available in the UK. The Pirelli Citynet Camper is not available in 225 section (as yet) so the XC seems to be the only camping tyre specified at this size. Regards, Mike.

[Guest Derek Uzzell]

First things first... I should have emphasised the need to ensure that your vehicle's tyres are appropriately matched and it's probably easiest to quote from Michelin's handbook on this. "Except (in certain specific cases)....the ideal fitment for optimum performance is always to have identical tyres all round.....The tyres fitted across an axle should be the same, ie. size, type, radial or cross ply, load and speed ratings. Note that it is illegal to fit cross ply tyres to the rear if radial tyres are fitted to the front axle." (Vehicle Construction and Use Regulation 26 goes into detail on the above.) Thus, regarding the ply-rating factor, you should not fit tyres with different ply-ratings on the same axle. This means that your motorhome's front wheels can carry 6-ply, 8-ply or 10-ply rated tyres on BOTH wheels, but NOT one 6-ply + one 8-ply, or one 8-ply + one 10-ply, etc. Similarly for the vehicle's rear axle(s). Consequently, if your 'van is fitted with (8-ply rated) XC Camping tyres all round and you need to replace just one, you should replace it with an 8-ply rated tyre (preferably another XC Camping) and not a tyre with a different ply-rating. (Yes, I know it's complicated!!) Alf M: (Basically repeating what's been said before.) Agilis 81 in 195/70 R15C size has a load/speed index marking of 104/102R. On a vehicle with 'single-wheel fitment' axles (ie. with one wheel on each end of the axle) this equates to a maximum axle load-bearing capability of 1800kg at approximately 106mph. So, unless you are into robbing gold bullion vaults or your Talisman is equipped with a rocket booster, your new Michelin tyres should serve you well. (I had Agilis 81 tyres fitted to my Herald and had no complaints.) Michelin's (single wheel fitment) axle-load/inflation pressure data for Agilis 81 195/70 R15C are as follows: 1800kg - 65psi 1640kg - 58psi 1480kg - 51psi 1300kg - 43psi Mike: Michelin gave me no details about why Agilis 101 215/75 R16C had been dropped from their range (lack of demand perhaps?) nor whether there would be a replacement. They did tell me sometime ago that 225/70 R15C XC Camping wasn't included in their UK range but could be obtained from abroad via special order. I've seen just one test report on a motorhome fitted with this particular tyre. It was a French article on an Esterel A-Class and the handling was highly rated. Knowing this design was Mercedes Sprinter-based (which usually results in test-report comments about super-comfortable ride but 'sloppy' handling) I noticed it was carrying XC Camping tyres. I suspect these were running at the full 80psi maximum pressure and would have firmed up the springing significantly.

[Guest Alf W]

Thanks for the references above and a salutory tale. I arranged for the Michelins to be fitted this week but on Wednesday headed south on the A1 from Edinburgh to Northumberland. The Pirelli tyre on the O/S rear, formerly the spare (for too long obviously)completely blew. The shed tread wrapped itself round the hand brake cable and applied the brakes. I therefore stopped in an almost straight line, very rapidly and with a lot of smoke, but no other damage. So don't put off getting your tyres up to scratch !!! And thanks to Green Flag for a very speedy and efficient response. They lifted the M'home onto a truck and took it to their local depot to change the wheel - it was too dangerous to attempt it on the dual carriageway. All done with a smile and great efficiency.

[Guest Derek Uzzell]

Bet that pushed your heart-rate up!

[Guest john steggles]

I have a Hobby 650 Fse and have done just over 22,000 Kms. The front nearside tyre is now down to 2mm tread depth, the offside is 3.5mm and the rears are still 5.5mm. Is this amount of wear normal for Michelin camping tyres? I have also noticed that the inside edges of the front tyres are more worn than the outer edges. Could tracking be a problem? What should the correct tracking be for a Hobby with Alko chassis? Thanks anybody for any info.