what's the offset on the stock legacy wheels?

Anybody know? Just wanting to compare to aftermarket ones I am finding for sale...

[quote name='scubie02']Anybody know? Just wanting to compare to aftermarket ones I am finding for sale...[/quote] +55 Kevin

thanks! So what do I need to be looking for in aftermarket wheels? I'm just looking for something cheap for use with winter tires...

+55 will be tough to find. I'm running +53 Prodrives for my winter wheels. Rotas might be an inexpensive option, even though they're the wrong offset, at +48. I think they're around $500-$600 per set, which is quite cheap for 17s. Kevin

With the lower offset of the rotas, do we have to take into consideration the larger brakes of the Legacy GT? I guess what I'm asking is that Rota has wheels that specify clearance of the STi's Brembos. Do we need to worry about clearance of our brakes too even if the wheels are 17"?

[quote name='Th3Franz']With the lower offset of the rotas, do we have to take into consideration the larger brakes of the Legacy GT? I guess what I'm asking is that Rota has wheels that specify clearance of the STi's Brembos. Do we need to worry about clearance of our brakes too even if the wheels are 17"?[/quote] Nope. The STi is an issue because of the caliper size. The GT doesn't have that same consideration. Kevin

The Rotas are a lower offset but they are also 7.5 inches vs. 7 inches. You can fit a 215/45/17 tire on a 7.5" wheel without any issues. A perfect fit would be a 225/45/17. I will be using Rotas this winter. Tom

can someone explain what these numbers mean ? offset ? 225/45/17 ?? // offset / size ? i am just trying to increase my knowledge of wheels... the upgrade bug has me... help ....

Keep in mind that the offset measurement while being a static dimension from centerline is still a dynamic dimension as it relates to the width of the wheel and suspension geometry. The offset doesn't have to be exactly +55mm, but it should be close for the same size wheel. A wider wheel will allow you to deviate a little more but still you have to try to keep close to original to keep from putting undue stress on the wheel bearings and suspension components. A taller or shorter wheel/tire combination will mess up your speedometer/odometer reading as well as change the suspension geometry that the offset measurement relates to. With a shorter wheel, you'd want to decrease the offset, and with a taller wheel you'd want to increase the offset. Sadly, most of the people in the tire/wheel business these days don't understand how this all works. If the offset isn't exactly what it's supposed to be, they can't help you at all.

225= tire width 45= aspect ratio or sidewall height, the smaller the number the lower the profile 17= the tire size

[quote name='RoundBoy']can someone explain what these numbers mean ? offset ? 225/45/17 [/quote] It's a messy mix of the metric system and the American system. Wheels are most often measured in inches in the US. Our Subarus come with the dimensions stamped on the inside of the wheel spokes as measured in inches. I have 17" x 7" wheels on my GT. There are two letters after that which are "JJ" which refers to the lip style of the wheels. 17" in diameter x 7" wide at the lips, JJ = 17x7JJ The offset is the measurement of the mounting pad (where the lugnuts go) as it relates to an imaginary centerline of the wheel. A 7" wide wheel's centerline is 3.5". The offset is measured from that point either towards the nice looking side of the wheel which is considered a positive offset (nearly all FWD cars have these wheels) or away from the outside of the wheel which is considered negative offset. (Think of the old RWD wheels.) A different way of stating the offset is called backspace. That would include the offset measurement and the distance to centerline in one measurement. You can only compare backspace dimensions with wheels of the same size unless you want to do the extra math. That's probably why they use offset instead. Tires are expressed in millimeters, percentages, AND inches. The tire has 225mm wide tread The sidewall is 45% of the tread width The tire fits on a 17" wheel. 225mm / 45%of 225mm / 17" = 225/45/17 The letters after the numbers such as ZR, WR, etc. indicates the speed rating of that tire. I've got some WR's outside that are rated to 168MPH. (No, I've never been above 128MPH on them.) ;) Does that help?

yep.. def does ... now i just need to relate that to what wheels fit / don't fit. i understand wheel size being the same is importiant because of speedo , etc.. width is fine as long as you physically fit in the wheel well.. why does the sidewall size matter? A 17" wheel is a 17" wheel.... unless its dependnet upon the rims you put it on...

So, does that mean that the 17" Rotas that I had on my 03 WRX will fit on my LGT?

[quote name='RoundBoy'] i understand wheel size being the same is importiant because of speedo , etc.. width is fine as long as you physically fit in the wheel well.. why does the sidewall size matter? A 17" wheel is a 17" wheel.... unless its dependnet upon the rims you put it on...[/quote] Okay, Let's start by going back to the speedo issue to clarify for future readers. Each wheel/tire combination has an overall diameter and radius. The diameter is the distance from one edge of the tire to the opposite edge of the tire as measured across the face of the wheel. The radius is simply half of that amount. It's the distance from the center of the wheel out to the edge of the wheel. The radius is really the important part since the car doesn't care how big your tires are, just how far it is from the center of the hub to the ground. This affects the speedometer/odometer (which in turn affects the cruise control), gear ratios of the transmission, and the stresses put on the suspension. I'm going to make up some dimensions for example sake, bear with me! I have a wheel/tire combo that is 30" in diameter overall. The wheel itself is 20" in diameter and the tire has a 5" sidewall. 20"+5"+5"=30" Half of 30" is 15" and the speedo is indicating it's speed based on the idea that there is 15" between the hub and the road in the form of a wheel/tire set. If we increase the wheel by 2" so that it's a 22" wheel, we need to [u]decrease[/u] the sidewall by the same amount so that we end up with 30" overall. 22"+4"+4"=30" which is still a radius of 15" for the speedo. By decreasing the sidewall height, we've changed the aspect ratio for that tire. As I said above, it's kind of a messy way to measure a tire which is probably the reason that tire size calculators exist! A tire measuring 205/45 and a tire measuring 245/45 are not the same height because one is 45% of 205mm and the other is 45% of 245mm. Now let's take it the other direction. (Here's where sidewall measurements really give you a workout!) Again we have a 20" wheel with a 5" sidewall tire. 20"+5"+5" = 30" The tread is 7" wide. The aspect ratio is going to be considered 70%. (71.428) If we increase the tread width to 9" the sidewall will increase to 6.3" high for the same 70% ratio. So we need to decrease the ratio to keep the tire the same size in diameter. Now we need a tire that is on 55% instead of 70%. This would be so much simpler if they just measured the sidewall independant of the tread width! As far as wheel width goes. You can't put drastically different width tires and wheels together safely. We've all seen lowriders with tiny tires on wide wheels and it's an accident waiting to happen! Most tire/wheel combinations tend to have roughly 1-1.5" more tread than the width of the wheel provided that the sidewall is tall enough to compensate. Lower profile tires must be closer in size. Let me use some highly artistic diagrams to illustrate my point: (___) = :) /___\ = :( \_ / = :( Wheel width and centerline & offset/backspace measurements are related to an imaginary line made by the strut if it were to reach all the way to the ground. The forces exerted on the strut are placed on the tire's tread at this point as it meets the ground. In a simplistic sense, the focal point here would be between the centerline of the wheel and the offset line. There is much more to this than I can explain. I'm not even sure that I know enough to explain it properly. We kind of need to trust the chassis designers for this kind of stuff. Ideally, when looking at changing tires and or wheels, there are three things to keep in mind to keep from screwing yourself over. Maintain the same overall diameter of the wheels. Maintain the wheelwell, fender and suspension part clearances. Maintain the same contact patch point on the tires. There is a fourth and fifth that I'd like to recommend based on my experiences. Lessen the weight of the tire wheel combo or you will be slower. Wider tires don't seem to fit in the grooves that semi trucks create on the roads. It's no fun wandering back and forth within these grooves that you don't fit in any longer! Trust that the engineers did it right!

OHHHHHHHHHHHH I can see... thanks for the info... so... its just easier to : 1) Get reviews in the tire you want 2) use a tire calculator to see if the offered ratios in the new tire match the OE subaru's (215/45/17) 3) profit

[quote name='bisk']So, does that mean that the 17" Rotas that I had on my 03 WRX will fit on my LGT?[/quote] I am relatively new to the Subaru world so I don't have all the numbers in my head for various models, but I can tell you this much. It would seem that the wheels on my Wife's '03 Legacy are the correct dimensions to fit my '05 Legacy. The front brakes could interfere but otherwise the dimensions seem to be the same overall. I do know that her wheels are also +55mm offset. The are 16" x 6" (I think) wheels. The bolt pattern is the same as well. That being the case, I'd bet that most of Subaru's wheels are interchangeable. It's not very common for manufacturers to change suspension geometry enough to require different wheels for each platform or model year. (Within reason) I'd suggest that you measure and see if the wheels have the same diameter to start with. Most wheels are cast with the offset measurement indicated on the backside along with the wheel dimensions. I'll bet that all Subaru's are using the same bolt pattern. I would also hope that they are using the same centerbore.

[quote name='RoundBoy'] 1) Get reviews in the tire you want 2) use a tire calculator to see if the offered ratios in the new tire match the OE subaru's (215/45/17) [/quote] I hope it's that simple! :D When searching for new tires/wheels for my GTP, I discovered that the engineers gave the GTP the biggest tire that was econimically and "engineerically" (yes, it's a word, I just made it up :) ) feasible for that size wheel. I actually couldn't buy anything different in size that would fit that wheel as well. I made the mistake of going with wider, larger wheels and actually decreasing my overall diameter a little bit. My speedo was off by 4 MPH at 90 MPH, the car was slower to get moving, it didn't fit the ruts I mentioned in one of my previous posts, and after driving on them for about a year, I took off that set of wheels that cost me $1400 and went back to better stock size tires on the factory wheels! Sure they looked nice, but it wasn't as much fun to drive! I also gained 4/10ths in the quarter mile! It was then that I was reminded AGAIN that I'm simply not equipped to re-engineer a car to my benefit in some cases. You could opt for a tire with a little more tread width on the factory wheels and probably be okay. Many manufacturers would give both the standard size and the optional "beefier" size on the tire chart stickers years ago. But be aware that heavier tires are [b]always[/b] going to slow you down. Extra rolling resistance will also slow you down! I'd recommend a better rubber compound instead of increasing the tire size! We put some Bridgestone Potenza G009's on my Wife's '03 Legacy a few months ago. They were a vast improvement over the RE-92's that she had. They were also CHEAPER than another set or RE-92's!

Ok, so I saw an add for wheels/tires that came off a wrx that said "5x100 with 47mm offset"--would these be ok on a legacy and whats the difference in offset going to mean...

people mentioned the alternate bridgetone tire (the one that is offered on AUZ / EU cars standard) . i forget the model number. Acording to tirerack.com .. they are the exact same size... and get good reviews here... might be a good bet.... either way... i am hard pressed to dump a pair of brand new tires... unless they cause me to fly off the road at any speed. My NEXT pair will be a different set .. I can 100% guarentee

[quote name='scubie02']Ok, so I saw an add for wheels/tires that came off a wrx that said "5x100 with 47mm offset"--would these be ok on a legacy and whats the difference in offset going to mean...[/quote] Hmmm. Well, I'm not sure if 5x100mm is the correct bolt pattern or not. I would guess that it is though. (See, it's not like you can just go measure a 5 bolt pattern. You need to consider the arc between two bolts to get an accurate measurement.) Without knowing the wheel's size as well as the tire's size, the offset doesn't mean a whole lot. But, in general the wheel will stick out (away from the car) 8mm further. This could have a few different effects. It could work just fine but possibly put more stress on the outer wheel bearing. Wheel bearings that have integrated sensors can be kind of pricey! It could move the "contact patch focal point" either more to the center of the tire or more to the outside edge. It would probably widen the "track" by 16mm or more unless the tires were narrower in the tread than what is there now. That sounds great, but it may change the handling characteristics and driveability in a negative manner. With more info, this could work out fairly well though.

The legacy does have a 5 x 100 bolt pattern, and I still think the general consensus is that 16" wheels will not be big enough to fit over the Legacy GT's brakes. Someone could try it to find out, but don't get your hopes up. :D

You can got down to a +42 mm offset with no probs whatsoever. :) Start lookin!

They are 17" wheels, but were described as above as far as offset. I think he said the tires that he had had on them were 225/45/17's.

[quote name='scubie02']They are 17" wheels, but were described as above as far as offset. I think he said the tires that he had had on them were 225/45/17's.[/quote] Okay. 225/45 is going to push the "focus point" further out than the 215/45 because the tire's a little taller until the tread is worn down. Without studying the strut angle through it's range of travel we can't tell how much. I would guess we are looking at an estmated 1-2mm at rest. The change in offset is going to move the "focus point" back in 8mm though. You are looking at losing 6-7mm of tread on the inside edge and gaining 11-12mm of tread on the outside edge. The track measurement will be 26mm wider than stock. (13mm per side) The inside track measurement will be 10mm wider as well. (5mm per side) I don't know what all of this means with relation to a Subaru. It may be a great improvement or it could actually reduce the contact patch of the tires because the weight is no longer spread evenly across the tread width. BoxerGT2.5, I'd be nervous about going down to a +42mm offset when the factory wheels are +55mm! But, what do I know. Subaru's are new to me. If +42mm has been working for everyone else, who am I to argue?

[quote name='Trent Bates'][quote name='scubie02']They are 17" wheels, but were described as above as far as offset. I think he said the tires that he had had on them were 225/45/17's.[/quote] Okay. 225/45 is going to push the "focus point" further out than the 215/45 because the tire's a little taller until the tread is worn down. Without studying the strut angle through it's range of travel we can't tell how much. I would guess we are looking at an estmated 1-2mm at rest. The change in offset is going to move the "focus point" back in 8mm though. You are looking at losing 6-7mm of tread on the inside edge and gaining 11-12mm of tread on the outside edge. The track measurement will be 26mm wider than stock. (13mm per side) The inside track measurement will be 10mm wider as well. (5mm per side) I don't know what all of this means with relation to a Subaru. It may be a great improvement or it could actually reduce the contact patch of the tires because the weight is no longer spread evenly across the tread width. BoxerGT2.5, I'd be nervous about going down to a +42mm offset when the factory wheels are +55mm! But, what do I know. Subaru's are new to me. If +42mm has been working for everyone else, who am I to argue?[/quote] I don't think anyone is consistently running +42 offset. Just saying that it would fit without any rubbing. I am running with a +47 mm offset. I tried +43 w/ no probs, but wouldn't go much lower than 42. :)