Honda Car Forum

I want to put an 18" Medusa rims onto my Honda Civic 2006. And I want the tyres size - 225/30/18.His answer is;TYRES WOULD BE NUETON ATR SPORTS SILICA COMPOUND TYRES 235/40X18 USING THIS SIZE WILL KEEP YOUR SPEEDO SPOT ON !! 225/30X18 WILL MAKE YOUR SPEEDO OUT BY HEAPS !!Anyone please explain what he mean and do you agree with the seller?ThanksThanks all for their answer. I don't know who to pick for the best answer. Still thinkingjust check out a website and it said this;HONDA CIVIC EX LX 2006BOLT-PATERN - 5x114.3 (5x4.5)OFFSET RANGE - 35 to 45 WHEEL RANGE - 16x6.0 to 20x8.5OEM TIRE SIZE - 205/55-16 (205x632mm )MAX TIRE DIMENSION - 225x660.0 so does it mean my max tire is 225? what is the 660 mean?http://www.specialrims.com/ChromeRim...20LX&year=2006

it means that it won't mess wit your speedometer "spot on"

What he means is that the Rim Size + Tire size will not affect your speedometer in your car as far at the reading is concerned. Most of the time if you up-size your tires you will mess up the speedometer because the tires are either spinning slower or faster than the factory tires (because they're either bigger or smaller than factory specs).

225/30 is a much smaller diameter tire, so when driving at 55 or so your speedo will display 60. however with 235/40 itll be closer but still off, when driving 55 your speedo will show 53, and 235 may be too wide for that car. i would run 215/40/18 that would provide an unnoticable difference.































edit: you can use this http://ww

The 225 tire is smaller in diameter than the 235 tire. Your spedo works by counting the revolutions of the wheels. If you go to a smaller diameter tire the spedo counts the revolutions but with a smaller tire you aren't traveling as far. For example the 235 tire travels 79.8 in. per revolution the 225 tire travels 73.2 in per revolution, so the 235 travels 6.6 in. farther than the 225. So if you put the 225 on when your spedo reads 60 mph you are actually doing 55 mph. so the seller is correct. If you bump up to the 20 in rims the 225 tire will get you close at .3% over speed- 60 mph on spedo is 59.8 mph actual speed.































www.miata.net

It depends. What is the original tire size that came on your Honda? You can go to a tire website (such as Tire Rack) and find out what the diameter of the original tires is. Often the "specs" for the tire will show you how many revolutions (or "revs") per mile you should get.The 225/30/18 tire would have a diameter of about 23.3 inches, and would have between 880-890 revs/mile. I had to calculate these out because I could not find a tire of this size online.The 235/40/18 tire would have a diameter of 25.4 inches, and have about 820 revs per mile. I found several tires in this size.Pick the tire that is closer in diameter to your original equipment tire. If you don't, your speedo could be off 5-15%! That and your gearing would be all jacked up.Other considerations are tire rub due to tire width, wheel offset, and suspension mods. Unless you know someone with the exact setup with 225/30/18 tires that doesn't have any problems, I would suggest contacting Tire Rack. They are very good at knowing what will and what will not fit for a particular car. The also provide wheel and tire modification suggestions that they have already "fit-tested."FYI, Tire Rack has the OE size for a Civic SI Coupe listed as a 215/45/17 (24.6 " diam. & 848 revs/mile). In your case both options you mentioned in your question would have about a 4-5% speedo error (at 70 mph indicated, the 225/30 would have a true speed of 67 mph, and the 235/40 would have a true speed of 74 mph).They listed the optional 18" tire size that would work as a 215/40/18. This tire has a diam. of 24.8 inches and about 839 revs/mile (closest to your OE specs). The speedo error would be about 1%, and not even noticeable.Even if you don't buy from them, use their info as a starting point, and get something close to their suggestions.{EDIT: The Miata tirecalc link is very helpful for comparing tire sizes, but it is only a starting point. It does not consider rolling resistance and tire "squat" when calculating revs/mile and speedo error. Use the tire manufacturers actual data for accurate comparisons.}{EDIT: Call the Tire Rack or go to the website! They will tell you everything you are asking about in about 5 minutes. It will be way easier than trying to type it all in here.}