This is my first post on the BR and I would like to start by saying how much enjoyment and useful advice I have gained while lurking round the margins. The collective wisdom of tens of thousands of motoring years is amazing. So on to the question...
I had recently to replace a single (damaged) tyre on my 2007 Forester. My local independent supplier, who undercuts Kwikfit by considerable margins was apologetic when the bill came to aprox £112 for a 215/60 R16 Yokohama Geolander G900 V rated. Replacement Bridgestones on my previous Forester had been about £65. Any suggestions for a cheaper major brand tyre when other replacements will be required in about 5000 miles? Also, how important is it to replace all tyres at the same time as suggested in the manual and is it acceptable to have one brand at the front with another of the same size and rating on the rear? At present I have two almost new tyres on the front wheels and part worne on the rear.
Thanks in advance
Alfalfa
|
The price for the new tyre is about right. I paid about the same if not more for two Geolanders about 18 months ago.
I think because the car is 4WD, it is better to have all four tyres with similar levels of tread. However, if you do no off-roading, you find a different more road focussed tyre for less. That is whay I intend to do when I replace the tyres on my Subaru.
On our first Forester we also replaced Geolanders with Bridgestones which were cheaper and more comfortable.
|
|
Pretty important to have all four tyres the same type with the same tread depth on a Subaru. It's best to swop front to back at every service to even out the wear. If you have uneven tyres, you will cause accelerated wear to the differentials. How much is debatable, but it will occur.
|
Thanks for the very quick replies Espada and nick. My tyre supplier was a bit sceptical about replacing all four as he reasoned that the difference in tread depth between new and part worn was often no more than the difference that developed as a result of different wear rates between front and rear. He also said that different inflation pressures would also give differences in rolling diameters. My last Forester wore the tyres pretty evenly 25000 at front and 30000 at rear. Has anyone actually come across damage caused by not fitting four new tyres at the same time?
Again thanks for the prompt reply
Alfalfa
|
Has anyone actually come across damage caused by not fitting four new tyres at the same time?
No at least not yet!
|
|
Nope, never do it! I'd imagine it would take many miles for any significant damage to occur. But I wouldn't like to risk it.
|
I hear these stories about differentials wearing due to different rolling radii... but if so, why don't they wear when 4wd cars go round corners?
Answers please?
:-)
|
|
They do, but not much, same as any car. But you don't continually go round a corner. With uneven tyres, from the diff's point of view, you are on a slight curve all the time. Hence the wear. Plus there is a centre diff, which will be operating if the front/rear rolling radii are not within spec.
Edited by nick on 26/02/2008 at 12:35
|
Quotes from the handbook of my Subaru Legacy:
''To maximise the life of each tyre and ensure that the tyres wear uniformly, it is best to rotate the tyres every 10,000km (6200 miles)...switch the front and rear tyres on the same side of the vehicle;
For safe operation, Subaru recommends replacing all four tyres at the same time.
WARNING!
All four tyres must be the same in terms of manufacturer, brand (tread pattern), construction, degree of wear, speed symbol, load index and size. Mixing tyres of different types, sizes or degrees of wear can result in damage to the vehicle's power train.''
Must be an urban myth then! ;-)
Edited by nick on 26/02/2008 at 13:03
|
Geolanders aren't known as Geosquealers for nothing so if you don't do any off road work then a decent set of ordinary road tyres with stiffer sidewalls will improve the handling - the stock size 215-60-16 is not a common size and a bit limited in choice of makes (Michelin's are even dearer than the Yoko's) so as I also shall soon need 4 new tyres I'm considering some Nokian NRVi at about £75 per corner from a local tyre shop but also heard good reports for Vredestein Sportracs ( which available but hard to find) and Falken and Kuhmo's. Some folks use size 225-55-16 which a much popular size and greater choice of makes (The rolling radius is about the same so speedo will not be even further out - abt 10 pcnt over reading on my car!)
|
If you want to stick with the original size, have a browse here.
I recommend these people 100% and Vredesteins 200%
tinyurl.com/26xmxd
|
Pleaides and gordonbennet thanks for the useful information on alternatives to the Geolanders.
Nick I note your quote from the hand book but it was reading this that led to my other question. Has anyone direct experience of transmission damage caused by using the same sized but differently worn tyres on a modern 4x4. The central diff should allow for some variation in rolling radius and is probably working a lot of the time. If you have driven an old school 4x4 where selecting 4wd simply locked front and rear axles then you would certainly have experienced the considerable amount of transmission wind-up and kangarooing that occurred on straight roads.
There must be thousands of Range Rovers, Discoverys, Quattros, Subarus, VW Synchros etc. Do all the owners regularly rotate the tyres and replace 4 at a time??
Cheers
|
|
No direct experience at all. Maybe Subaru are wrong? Or just covering their backsides? There must also be plenty of 4x4 vehicles with worn diffs that get put down to 'wear and tear'. Your call. I'd rather do as the manual says.
|
|
|
The handbooks for all my recent 4x4s -- Citroen BX, VW synchro, Daihatsu -- have the same advice as Subaru so I am inclined to accept there is a sound engineering foundation for that advice. Not all 4x4s have central differentials or evenly balanced sharing of drive so the potential for uneven wear on tyres and transmissions is there. I suspect the drive train is going to be more exaggerated where someone leaves a couple of well-worn but legal tyres on while replacing those on the other axle. I have always followed the advice to swop the tyres front to back and end up replacing all four at the same time which can seem steep but doesn't cost more in the long run unless tyre prices are rising rapidly month on month. Mostly it is the idea of forking out £1500 or so for a new differential that concentrates the mind on smaller preventive costs. Another thing to bear in mind about the later generation of ECU-controlled all-wheel drive systems is that worn tyres are another factor that may not be allowed for in the transmission algorithms. One or two popular 4x4s can already be caught out in relatively everyday situations on loose gravel, sand or even slippery grass.
|
Volvo crosscountry awd cars also have the same warnings and have had powertrain problems when advice ignored.
When we had an Outback we followed the advice to swap from to back but not side to side in the manual, never had a set of tyres wear so evenly before or since that car.
StarGazer
|
Hi,
I have a 2006 Outback, and would ask you guys for your advice on what to do if you suffer a puncture on one tyre that cannot be repaired.
Are you expected to put new tyres all around (or on the same axle) to balance the tread hight?
dk
|
|
Good question! I have no answer. I just keep my fingers crossed, my last puncture was in 1984 (touch wood)
|
|
|
David K this was my problem hence the OP. I put the unused spare on one front wheel and the new tyre on the other. But if it happened again?? I don't think I would want to cough for four new tyres.
Alfalfa
|
Hi All,
Not quite an answer to the original query, but have you found this thread:
www.honestjohn.co.uk/forum/post/index.htm?t=53983
Some very interesting info that explains why my 2001 H6 Outback understeers more with Kuhmo tyres on the front rather than Yokohamas. All to do with tyre wall stiffness! Is this why manufacturers spec certain tyres for their cars ? And the cynic in me thought it was just about the money . . . . .
My take on replacement tyres is:
1 - ask the guys who've managed to get 300k out of their Subarus how they treated tyre replacement?
2 - assume Subaru are quoting the technically correct worst case scenario, but that because their cars are over engineered you won't break a diff (my preferred answer).
3 - try a secondhand tyre if you have to scrap 1 part way through its life.
I'm wondering about one pair of very off road tyres for my Outback having . . . . . wait for it . . . . nearly got stuck towing a trailer of logs out of a wet, muddy field, so will follow this with interest.
|
I have a similar uncertainty about my '94 Outback 3.0Rn: replace with Yoko G600 tyres or go to Kumho KU31 which seem less suitable for occasional offroad use?
Or could I go for KL17s although they are 225 not 215 and have rims of 4 not 7??
Grateful any views.
|
|
|
|
|
|
