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View Full Version : Can I put 50's on 17" wheels?



mrtew
04-01-2003, 07:55 PM
I want to get 17 inch wheels and tires for my new Si, but I want bigger tires. Does anyone know if they will rub or cause any other problems? I live in Detroit where the roads are pretty bad so I don't want to lower my car at all... I can't take the risk of making the ride worse or damaging the car by hitting a "canyon". With the 40's or 45's the tires look way too small at stock ride height, because there is WAY too much air around the tires. I think 50's would make it ride smoother, fill up the wheelwells, and protect the wheels more. Giving it a SUV look wouldn't bother me because 70 percent of the vehicles on the road here are SUV's so it will still look like a car here. And the speedo error and power loss wouldn't bother me either. But rubbing definitely would. Can anyone tell me if this is a bad idea, or just a different one?

FailureToStop
04-01-2003, 10:48 PM
You didn't specify what width you were getting. But with 50's you will have an overall diameter of:

185x50x17 = 24.28"
195x50x17 = 24.68"
205x50x17 = 25.07"
215x50x17 = 25.46"
225x50x17 = 25.86"

Stock is:

195x60x15 = 24.21"

The biggest difference would be the 225's which would be a difference of +1.65". Assuming you keep the stock springs you shouldn't have a problem. If you divide the 1.65/2 you would get .83". This is approximately the change in the gap between your tire to your fender.

Contrast this with the drop from Progress, Eibach, etc. (~1.5") difference. With these springs there would approximately a decrease of 1.5" in the tire to fender gap.

There haven't been any reports that I have seen where there were any rubbing issues with a 1.5" drop (I haven't had any with my Progress springs). So a .82" drop won't be a problem.

Of course your speedo would be off, you would have slower acceleration, your MPG would drop and... hell your EP would do a Suzuki Samurai immitation easier and you couldn't corner worth shiet. :( But I bet you could go offroading and you would be hella faster!

Tekdemon
04-02-2003, 12:03 PM
Actually I think his MPG might go up because of the bigger wheels if he drives on the highway a lot...

That friggin close 5th gear always keep my engine RPMs so frigging high on the highway, bigger diameter tire/wheels should lower those RPMs and change the final ratio of engine RPM to distance.

But yeah you would accelerate worse, and corner like crap...I wouldn't bother...a transmission swap would make a lot more sense =P

JoshSI
04-02-2003, 03:19 PM
Just get some 16" wheels and get 45 series or 50 series. If you get the 17s with 50 series thats too far off from sotck diameter. Your speedo will be all whack!

Rueda del Queso
04-02-2003, 05:57 PM
The speedo wouldn't be that bad, only 6.8%. So if your speedometer said 60 you would really be going 64, you would just have to remember to keep 4 or 5 miles under what you normally go. Also, this would make your odometer be lower than actual. It is a little deceitful, but if you resell it you'll get a price for a car with 6.8% less mileage.

mrtew
04-02-2003, 08:12 PM
Originally posted by Tekdemon
Actually I think his MPG might go up because of the bigger wheels if he drives on the highway a lot...
But yeah you would accelerate worse, and corner like crap...I wouldn't bother...a transmission swap would make a lot more sense =P

Thanks for the great responses.... keep them coming!!! Yeah, I think I would have a higher top speed, better mileage, longer warantee (because the odometer would be off too), better visibility, smoother ride and better ground clearance for offroading, when compared to 40 or 45 series tires! Also, compared to the stock tires I think that the 17's with 50 series would have a much wider contact patch and a slightly smaller and stiffer sidewall so cornering would be much improved, easily offsetting the slight increase in the height. Obviously this would nowhere close to a slammed EP on 40's but like I said, that is out of the question in 'lunar landscape' Michigan. Also I really don't think the acceleration would be hurt after I get up to 2000rpm anyway would it? I'd only lose that first second in the quarter mile and then my higher shift points might let me catch up anyway... not that I'm into drag racing, but I don't see how larger diameter tires could affect power after I get launched.

This is how I think it will look with the Enkei wheels and the big tires.

http://homepage.mac.com/mrtew/EnkeiWheels.jpg

gito
04-03-2003, 05:16 AM
I was thinking to do the same thing. I am just worried about bigger tires rubbing my car, but I am not gonna lower mine either., because I live in MI too... wierd