We have tested this as used never to use aircon. But travelling with small grandchild we did same journey from UK to here so used aircon, and used exactly the same amount of diesel… needless to say we now use it when needed.
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In testing session i was able to view at a well known establishment in Wolfsburg, i saw first hand by how much driving with open windows (at the front) increased the wind resistance and also reduced the stability of the vehicle due to the streamlining being reduced. Using aircon also increases the fuel consumption which on a decent sized engine is hardly noticeable.
Tyres: It is illegal to fit a radial build on the same axle as a cross-ply build. It is not illegal to fit a michelin and a pirelli on the same axle as long as they are both either radial or cross-ply. Summer and winter tyres must be the same on each axle. a M+S or all year tyre mixed with a summer tyre on the same axle is illegal.
It is advisable to fit approximately same profile on same axle but not illegal if you dont. Also hard kerbing or visible damage to the side wall, head for the tyre dealer and replace the tyre, you can not see what damage has been caused within the walls. It is not a case of it might give way, it will give way, just the timing remains to be seen.
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It depends on the vehicle and the Aircon. On my old Volvo you had to switch off the Aircon if you wanted to pull away with any pace. The Renault is barely noticeable likewise on fuel about 1 mile per gallon less maybe 2 at a push. Windows open a lot more as Roger said.
Actually, it is illegal to mix brands.
Here are the instructions from UTAC as issued to CT starions - IT VL F5 5 - WHEELS, WHEELS, TYRES, SUSPENSION 20 December 2017
in the absence of this information, corresponds to a speed higher than the speed
maximum of the vehicle.
If the expected index is equal to or greater than Q (160 km/h), winter tyres
marked M+S may have a lower index than that provided by the manufacturer,
but not less than Q.
Same structure for all tyres mounted on a vehicle (D diagonal, B
cross belt, radial R, flat running).
Type Same for all tyres mounted on the same axle (brand,
use category, structure, load and speed indices).
If all tyres on the same axle are retreaded, only the
definition of the type the brand of the retreader excluding the brand of origin of the
manufacturing. If retreaded and non-retreaded tyres are present on a
same axle, all tyres have the same original type and the retreader is
the manufacturer himself.
But not tread pattern/series - so you could fit two completely different Michelin tyres to either end of an axle and still be legal?
Which can’t be better than a Michelin on one end and a Pirelli on the other (assuming use, construction, load and speed indices match).
In Al’s case he would still have been better off finding a garagiste who could match the good tyre and I can’t help thinking he was taken advantage of by the bloke that insisted on selling him two tyres, whatever French law says.
Had it been me I’d like to think I’d have said “I can sort you out but you’ll need to buy two tyres from me - why don’t you ring round and see if you can get a match to the other side”.
The garagiste did not try to screw you, with modern cars, it is always mandatory or really recommended to have front or rear tyres to be changed in the same time. Having different level of wearing tyres can exercise a precharge on the differential and axles into the transmission, after 20.000 kms it can damage the differential or cause malfunction.
This is particularly relevant for modern Volkswagen Group cars (VW, Audi, Skoda, SEAT) with 4motion and Torsen all wheel drive transmission.
I have a Peugeot 308 wagon, it’s a front wheel drive, last month I had a flat front left tyre, it was brand new, just 2000 kms for both front tyres. The garagiste changed both tyres to preserve the differential.
Thanks Mark, i wasnt up to speed having been out of the automotive industry for almost 15 years. I stand corrected.
Sorry but your mechanic was ripping you off.
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Roads are not flat, they are cambered, add that to the different loads on each wheel as you corner or round a bend and the argument over loading differentials falls away. Most modern all wheel drives are viscous couplings and in the case of the amazing Subaru it’s off road capabilities are very good but not all wheels are in contact with the ground, hence why farmers like them. If they suffered as suggested then the system would not have worked for the many years it has.
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Sorry Maxine but that’s bollocks - differentials can cope with the output shafts permanently rotating at different RPMs, it is their entire raison d’être.
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It’s a lovely story!
This modern video explains more clearly why your garagiste is taking the mickey - https://www.youtube.com/watch?v=yYAw79386WI&t=339s
Fascinating stuff. What a knowlegable lot you are. I haven’t thought about retreads for years but Mark suggests they’re still on the go. The garagiste asked how much I wanted to spend and I said I’d prefer to keep the price reasonably low because I mainly tootle around country roads. The bill in the end was 133€ for two tyres, fitted. That was a lot less than I’d expected and now wonder if they were retreads. My French wasn’t up to following his technical jargon and he could well have mentioned this. I’ll have to check. Meanwhile, I was chatting to a French pal yesterday and he said it was standard practice to replace both tires on the same axle. This was accompanied by the obligatory Gallic shrug.
Yes, it is.
We were lucky when we had a puncture on our nearly-new car. We took it to a local tyre specialist, expecting a hefty bill for a replacement, but in fact he was able to repair the puncture on the spot and only charged us 10€. Needless to say, I now wouldn’t consider going anywhere else.
Avoid all the hassle with having to buy two tyres by giving the garage the wheel and telling them it’s the spare.
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They should be marked, but you might have to look carefully
I think this is still the pertinent legislation1:
The tyre should carry, amongst other things, the word “RETREAD”
1] How did we cope before Google?Just checked and they’re new – Kormoran, made in the Czech Republic. Never heard of this make but they seem to be doing the job.
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Sidewall damage, to my cost, is now a Controle Technique fail point
Good <deity> Mark - I thought I knew how differentials worked until I watched that - then had to watch it a couple more times before convincing myself that it really was describing what I already knew.
I think the problem is that, once it has finished explaining with the bars it skips forward much too quickly with no real explanation at all as to how you get from that to something that looks recognisable as a functioning diff.
This one is better, despite the narration that sounds like it was generated with a text to speech program working from a script written by someone who’s native language isn’t English.
Must try to understand limited slip diffs though.
PS - Al, what car do you drive?
The film was made to explain the theory to those with a Donald Trump level of understanding.
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