Tire size just making sure
-
tastethefear
- Junior Member
- Posts: 4
- Joined: September 12th, 2007, 12:35 am
Tire size just making sure
The 195/55/R15 will fit on the stock 15 inch rims right. Since standard 205/55/r15. What will the difference be on the 195 to the 205?
Last edited by tastethefear on December 2nd, 2007, 11:06 pm, edited 1 time in total.
it will be slightly narrower and shorter.
95 rs with custom short ram air, b&m short throw shifter, probe 2.0L header with 2 1/4" exhaust all the way back, catco high flow cat, apc high flow muffler with 4.5" tip, accel 8 mm wires, blaze red, cf altezzas, gun metal 17" mr7s, slotted cross drilled rotors on the way with hawk hps pads, red and white interior, other then that its stock.
they should
95 rs with custom short ram air, b&m short throw shifter, probe 2.0L header with 2 1/4" exhaust all the way back, catco high flow cat, apc high flow muffler with 4.5" tip, accel 8 mm wires, blaze red, cf altezzas, gun metal 17" mr7s, slotted cross drilled rotors on the way with hawk hps pads, red and white interior, other then that its stock.
-
wytbishop
- Senior Member
- Posts: 5554
- Joined: August 25th, 2004, 2:01 am
- Location: Edmonton, Alberta, Canada
205/55/R15...
205 is the thread width in mm.
55 is the aspect ration of the tire wall. That's the height of the tire wall from the lip of the rim to the tread as a percentage of the tread width. 205*.55=112.75mm
R is the speed rating of the tire.
15 is the size of the rim the tire is made to fit in inches.
Overall tire diameter then is 15" + 2(205*.55/25.4) = 23.88" for the stock tire size.
work it out and 195/55/R15 is 23.44" about .44" smaller in diameter, which corresponds to 1.38" less circumference. That means for every revolution of the wheel the car travels 1.38" shorter distance.
Now road speed is measured off of the differential gear so at a given rpm the speed displayed on the speedo is derived based on the stock tire size and the wheel traveling a certain distance for every revolution. The speedo doesn't know you've changed the tire size. So at a given diff speed, now the wheels are traveling a shorter distance and the speedo will read high...but not much. The more common problem is guys putting 17's with say an inch larger overall diameter. That's over 3inches more travel per revolution. Their speedo's will be noticably low.
I know 99% of you know this...but I'm bored.
205 is the thread width in mm.
55 is the aspect ration of the tire wall. That's the height of the tire wall from the lip of the rim to the tread as a percentage of the tread width. 205*.55=112.75mm
R is the speed rating of the tire.
15 is the size of the rim the tire is made to fit in inches.
Overall tire diameter then is 15" + 2(205*.55/25.4) = 23.88" for the stock tire size.
work it out and 195/55/R15 is 23.44" about .44" smaller in diameter, which corresponds to 1.38" less circumference. That means for every revolution of the wheel the car travels 1.38" shorter distance.
Now road speed is measured off of the differential gear so at a given rpm the speed displayed on the speedo is derived based on the stock tire size and the wheel traveling a certain distance for every revolution. The speedo doesn't know you've changed the tire size. So at a given diff speed, now the wheels are traveling a shorter distance and the speedo will read high...but not much. The more common problem is guys putting 17's with say an inch larger overall diameter. That's over 3inches more travel per revolution. Their speedo's will be noticably low.
I know 99% of you know this...but I'm bored.
94' RS/GS/MS/CF Monster Turbo...coming soon.
93' GS SE, the Black Beast, the former love of my life...soon to be gutted and crushed.
94' GS, black on black, now in several small pieces...and one large crushed piece.
2007 Mazda3 GT Sport --- super fun
2004 Honda RC51 --- Lost forever to some theavin' bastard
My Worklog
My feedback thread
Never attribute to malice that which can be adequately explained by stupidity.
93' GS SE, the Black Beast, the former love of my life...soon to be gutted and crushed.
94' GS, black on black, now in several small pieces...and one large crushed piece.
2007 Mazda3 GT Sport --- super fun
2004 Honda RC51 --- Lost forever to some theavin' bastard
My Worklog
My feedback thread
Never attribute to malice that which can be adequately explained by stupidity.