[utcadman]

I am looking at putting a staggered setup on the X3

Here are the wheel sizes I am looking at.

2011 BMW X3

Front Size: 19" x 8.5", 5 Lug, 120mm Bolt Pattern, 38mm Offset

Rear 19" x 9.5", 5 Lug, 120mm Bolt Pattern, 48mm Offset

Is this the correct size? Would this require spacers in the front.

Any help appreciated.

Thanks

Jim

[Lotus7]

Since these are the exact sizes and specs for the factory optional 369M and 309 staggered set ups (with the correct tire sizes) they should work fine as long as the wheels have the correct hub diameter to match the X3 (72.5mm). The published offset spec. is 45 +/- 2 mm, but obviously BMW is allowing 38 mm offset wheels to be used without spacers. Probably, they want to enhance the apparent staggered "look" by narrowing the track at the front slightly. It's also possible that they compensate for the offset change by using a little less toe-in at the front (possibly different alignment specs for the staggered set up).

The difference (at the front) is only 7 mm - Although most commonly sold in 12, 15, 20 and 25 mm offsets, Eibach does make a 5mm spacer with a 72.5 ring.

[utcadman]

Thank you very much! Yes my main question was if the 38mm in front was acceptable.

My new plan is to get the 309's with the Continental Extreme Contact DWS so before I dropped the change wanted to make sure!

Thanks

Jim

[Lotus7]

Originally Posted by utcadman

Thank you very much! Yes my main question was if the 38mm in front was acceptable.

My new plan is to get the 309's with the Continental Extreme Contact DWS so before I dropped the change wanted to make sure!

Thanks

Jim

The Conti DWS's are a nice tire with a very good "all-seasons" reputation and great owner feedback. What is your strategy for dealing with a possible flat?

[utcadman]

I will get a car kit and luck!

[XRP]

go with 10wide in the back

[Lotus7]

Originally Posted by utcadman

I will get a car kit and luck!

The Griot's Grarage kit is excellent, but is a little bulky.
http://www.griotsgarage.com/product/...rrivals&page=1

The Slime compressor and tubless plug kit is smaller and a little less expensive:
http://www.amazon.com/gp/product/B000ENQRD2
and
http://www.amazon.com/Slime-2040-A-T...1717151&sr=1-2

The Slime self-sealing "goop" is another way to go, but makes for a real mess if you try to have the tire properly repaired. I use it in my mountain bike (where you can throw away the inner tube) but would never put it in an expensive car tire.

[TN_3]

I've been happy with the ContiComfortKit...
http://www.tirerack.com/accessories/detail.jsp?ID=38

Also, which wheels are you looking to purchase?

[fedinand]

Originally Posted by Lotus7

Since these are the exact sizes and specs for the factory optional 369M and 309 staggered set ups (with the correct tire sizes) they should work fine as long as the wheels have the correct hub diameter to match the X3 (72.5mm). The published offset spec. is 45 +/- 2 mm, but obviously BMW is allowing 38 mm offset wheels to be used without spacers. Probably, they want to enhance the apparent staggered "look" by narrowing the track at the front slightly. It's also possible that they compensate for the offset change by using a little less toe-in at the front (possibly different alignment specs for the staggered set up).

The difference (at the front) is only 7 mm - Although most commonly sold in 12, 15, 20 and 25 mm offsets, Eibach does make a 5mm spacer with a 72.5 ring.

Using spacers in the front would push the wheels out more...the higher the offset the more tucked the wheel is (depending on width). Using 7 mm spacers up front would cause the offset to be 31...and thats going to poke out the wheel wells. The rears have a higher offset due to them being an inch wider than the fronts so they will "match" the rears...10 mm = about 3/8 of an inch so the rear's offset is compensated by the fact the rear wheels are an inch wider.

[utcadman]

Thanks for the help. Think I got summer winter thing figured out.

[Lotus7]

Originally Posted by fedinand

Using spacers in the front would push the wheels out more...the higher the offset the more tucked the wheel is (depending on width). Using 7 mm spacers up front would cause the offset to be 31...and thats going to poke out the wheel wells. The rears have a higher offset due to them being an inch wider than the fronts so they will "match" the rears...10 mm = about 3/8 of an inch so the rear's offset is compensated by the fact the rear wheels are an inch wider.

Thanks for catching the error in my statement, clearly the less the offset, the wider the track of the wheels.

Using less offset is the way to go, if what you are trying to maintain is in-line alignment of the outer edge of the tires (front to back). Unfortunately, the suspension geometry is almost always calculated based on the centerline of the tires. Usually, for optimum tracking one wants to maintain the "track" (lateral distance between centerlines of the tires) by keeping the centerlines of both ends of the car in line by maintaining the track independent of wheel/tire width. As you point out, this will result in less clearance at the fender lip with wider wheels. If all of the offset is allowed on the inside edge (by using more hub offset with wider wheels), you do maintain fender clearance, but risk inside interference with the springs, brake calipers, TMS pick-ups, and suspension brackets. Clearly, BMW has taken that into consideration with the staggered wheel set up and are using offsets that are the best compromise necessary for clearance, but possibly not the best for suspension geometry. The differences are so small, however, that they probably don't really make any "real-world" difference.

[Lotus7]

Originally Posted by TN_3

I've been happy with the ContiComfortKit...
http://www.tirerack.com/accessories/detail.jsp?ID=38

The Conti Kit is one solution in a jam, but keep in mind that using it will disable and damage your TPMS transmitter and most tire repair places will not agree to do a permanent (safe) repair on a tire that has had liquid sealant used inside.

As with driving any significant distance on a "run-flat", you're looking at a full tire replacement.

On the other hand, pushing a rubber/fiber plug into a puncture hole on a mounted tire at roadside is no fun at all, but will probably save the cost of a replacement tire.

[LEDZEP]

Originally Posted by Lotus7

The Griot's Grarage kit is excellent, but is a little bulky.
http://www.griotsgarage.com/product/...rrivals&page=1

The Slime compressor and tubless plug kit is smaller and a little less expensive:
http://www.amazon.com/gp/product/B000ENQRD2
and
http://www.amazon.com/Slime-2040-A-T...1717151&sr=1-2

The Slime self-sealing "goop" is another way to go, but makes for a real mess if you try to have the tire properly repaired. I use it in my mountain bike (where you can throw away the inner tube) but would never put it in an expensive car tire.

I have the Griot's kit in both vehicles. It is a little bulky, but you can also break down the components and store in multiple slots to ease that. I like the bag because it includes ample storage for other important things like cleaning products to get bugs off on long trips, etc. I added a small tube of rubber cement to each kit, to use with the plugs... just in case.

Having had a flat tire on a vacation trip with a run flat tire, I decided then and there that I wanted an option that at least gives me some control. You'll NEVER find a replacement RFT on a trip, and you'll be lucky if you can find a shop open nearby at all. If a tire is punctured at least with the kit I have a chance to repair it - thought it certainly wouldn't be much fun.