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      07-19-2012, 10:49 PM   #1
Stuart@BMRAutowerkes
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The Definitive Tyre Thread (FAQ inside)

The Definitive Tyre Thread

- ask questions
- find answers


OK itís a very common question on here with too many threads being created about what tyres should I buy, should I buy runflats (RFTs) or non RFTS, where should I buy tyres etcÖ Please read this thread first before creating a new thread about tyres!

You can ask questions in here. Thereís always the search button too.

Here are some common topicsÖ feel free to add to this down the bottom and Iíll update this post.
1. What are the advantages/disadvantages of runflats?
2. What are some good tyres?
3. Where can I buy tyres from?
list of threads started by forum members on specific tyres
4. What tyre size should I run?
5. Where should I get my tyres mounted?
6. What tyre pressure should I run at?
7. READ THE FAQ


1. Runflats are designed to do just that, allow the vehicle to operate safely in the sudden event of lost tyre pressure and/or allow the driver to continue driving up to a speed of 80 km/h in the event of a flat tyre for a few hundred KMs.
Advantages:
- Safety
- Convenience
Disadvantages?
- Stiff sidewall construction means a very firm ride and the tyres generally do not have as much grip as non-run flats
- Expensive, a lot more expensive than non-RFT counterparts which are better.
- Generally seen as more prone to punctures (hard statistic to track but people generally report more nails in tyres etc in RFTs than non-RFTs)

Itís my opinion, and that of many others, that non-RFTs are the way to go. Cheaper, better handling and providing more grip, these are all priorities to me above worrying about getting a flat tyre.

2. What are some good tyres?
Again a slightly subjective topic but the current cream of the crop is generally accepted to be the Michelin Pilot Super Sport. It has loads of grip (wet and dry), handles very well, wears well and has good road manners (i.e quiet).

Some other recommended tyres for different scenarios and indicative pricing.
Best overall: Michelin Pilot Super Sport ~$1,800
High performance: Yokohama Advan Neova AD08 ~$1,300 (very grippy in the dry, still impressive in the wet and good road manners)
Road legal track tyre: Toyo R888 ~$1,400 (even grippier than the Yokohamas, but rather noisy)
Good value all-rounder: Continental ExtremeContact DW ~$1,200. This tyre is priced very reasonably and has been getting good reviews from customers.
*: this canít be purchased at Continental tyre dealers in Australia as it was developed for the North American market. All these tyres are grey imports.
**: DW indicates Dry/Wet. There is also a DWS version getting around which means dry/wet/snow. There is no point purchasing the DWS for Australian conditions.
Kumho KU31s often come up in threads, these tyres are good for the price and on a 325i will do the job... on a 335i, I'd recommend something grippier.


3. Where can I buy tyres from?
Ideally, itís best to support local vendors where you can. Iíd highly recommend Tyrepower in North Melbourne, (03) 9329 7333, you can PM ĎVansí on this forum.

Otherwise, itís hard to beat www.tirerack.com. Good site for reading reviews as well.

If you need local rubber fast here are forum members recommendations:
Sydney: Tempe tyres, Taleb tyres, St George tyres
Melbourne: Tyrepower North Melbourne
Brisbane: TBA
Perth: TBA
Adelaide: TBA



4. What size tyres can I fit?

Use the search tool.

All E9X models can comfortably fit up to 19" wheels without any modifications.
20" wheels can fit as well depending on width and offset.
Generally accepted 19" fitment is:
Front: 235/35/19
Rear: 265/30/19 (255-275 works as well)


5. Where can I get my tyres mounted?
If you buy tyres online you'll need them mounted, most tyre places in Sydney will charge between $60 and $80 to fit and balance 4 tyres. Some members have reported the shop getting the shits with them due to not buying locally so this can be used to list all the places members have had tyres fitted before
Sydney: Tempe, Taleb, 7day tyres (Granville), Payless Tyres Hume Hwy South Strathfield
Melbourne: TBA
Brisbane: TBA
Perth: TBA
Adelaide: TBA

6. What tyre pressure should I use?
BMW/Manufacturers in general will suggest 30-32psi, which gives a more 'supple' ride.
This comes down to a matter of personal preference but most people will tend to run high 30s all around. This will see longer tyre life, better fuel economy and sharper handling. Don't overinflate your tyres though - this can decrease traction significantly and cause uneven wear patterns.
Try this out:
Front: 38psi
Rear: 38 psi.


Advanced drivers might tweak the tyre pressure on each axle to finetune their handling
A slightly lower front tyre pressure may reduce understeer, but again, many variables and recommended for advanced drivers only.

It's also worth nothing these are 'cold' temperatures, as a rule of thumb, when the tyres are hot and you go to check their pressures after some street driving they will gain +4psi.

If you look at the centre of your tread pattern, and notice wear occurring there and not on your sidewalls, this indicates overinflation
If the shoulder of your tyres wear quicker than the inside, this indicates under inflation.

Tracking & Tyre Pressures
Street tyres will get very hot on the track and as such they will inflate a fair bit temperature wise over what you think you've set it at. It's hard to say set it to xx psi as there are many variables to consider.
(or slightly lower than your street setup OR equal to OE spec) and going out for a few laps. After that, check your pressure to see what it's at, it might be 40psi, which would bring us to our ideal range of 38-42 for most tyres and applications.
When tyres get hot, naturally they'll start to lose a bit of stickyness and you'll feel the car squirm around a bit.
Do:
- start your first session with a lower tyre pressure
- check them constantly
- inspect the sidewalls for signs of underinflation

Don't
- use your street tyre pressure of 40+... many tyres will have a max of 50psi and on the track, you could easily gain 10psi which would post a safety threat


7. FAQ
Can I use non-RFT tyres on my BMW wheels?
Yes!

Will putting non-RFT tyres on my BMW void warranty/insurance?
No!

Can I put RFT tyres on aftermarket wheels?
Technically, yes, but the RFT properties won't work as the wheels don't have the special lip required to keep the tyre on the rim in the event of a flat

Can I repair a RFT tyre?
Manufacturer says no, but as long as it's not too close to the sidewall and you haven't driven on the tyre while flat, then yes you can get it repaired just like a conventional tyre

I bought tyres from tirerack, where can I get them mounted?
See point 5 above

If I put 19inch wheels on my car will the ride be bumpy?
Generally accepted that it will be due to the lower profile rubber, however if going from 17" RFTs to 19" non-RFTs then the ride would be comparable. It's rather subjective.

If I have non-RFTs and get a flat what should I do?
1. Carry a slime kit and compressor (available from Repco, Supercheap Auto etc)
2. Call for roadside assistance
3. Have a friend drop off a spare wheel (make sure they bring tools!)


What's the factory torque spec for our BMW lugbolts?
92 ft lbs... +/ 7ft lbs.

I've heard of lugbolts coming loose and becoming brittle with age - is this true?
Yes, especially when tracking the vehicle. Keep spares on you or at home, or for peace of mind change the lugbolts annually when tracking (or at least inspect them)

Do tyres go 'off'?
Yes! When purchasing new it's ideal if they have a build date within the last 12 months, 12-24months is getting on and if 24months + you better be getting them damn cheap.
If you drive a car (especially noticeable in high performance cars) that has tyres already 6-7 years old even if they've only done 5,000kms, the silica compound just degrades and they'll provide very little grip.
Be wary of tyre shops selling 'cheap' rubber that is already a few years old.



All advice is general and does not take into account your specific circumstances or rules and regulations of your state or territory.

Last edited by Stuart@BMRAutowerkes; 08-02-2012 at 07:34 PM.