Speedo

[cluv]

I have a question for you guys who like to crunch numbers. I've been wondering this for a while, so here goes............................

I run a 245/40/20 tire on the front, and a 275/50/20 on the back. The 1010 Tire calculator says at actual "60 mph" I'm actually going 61.9 mph with the front tires, and 55.7 mph with the back tires. So my question is............How fast should my speedo show at actual 60 mph?:confused:

I haven't been able to have any tire shop tell me exactly, let alone even offer a guess. I usually get the "It's hard to say..........." type answer.

I would just like to know, so when I'm on the highway cruising I don't have to worry about tickets and stuff like that.

Any help would be appreciated!:D

[da BoMM]

I have a question for you guys who like to crunch numbers. I've been wondering this for a while, so here goes............................

I run a 245/40/20 tire on the front, and a 275/50/20 on the back. The 1010 Tire calculator says at actual "60 mph" I'm actually going 61.9 mph with the front tires, and 55.7 mph with the back tires. So my question is............How fast should my speedo show at actual 60 mph?:confused:

I haven't been able to have any tire shop tell me exactly, let alone even offer a guess. I usually get the "It's hard to say..........." type answer.

I would just like to know, so when I'm on the highway cruising I don't have to worry about tickets and stuff like that.

Any help would be appreciated!:D

I'm gonna guess that the back wheels (drive wheels) determine your speed.

[Banshee]

I have a question for you guys who like to crunch numbers. I've been wondering this for a while, so here goes............................

I run a 245/40/20 tire on the front, and a 275/50/20 on the back. The 1010 Tire calculator says at actual "60 mph" I'm actually going 61.9 mph with the front tires, and 55.7 mph with the back tires. So my question is............How fast should my speedo show at actual 60 mph?:confused:

:D

both the front and rear wheels will be travling the same MPH, just the RPM will be differant

[mnunes]

I think it depends on which wheels are used for the spedometer. Since the car's traction control has to have sensors at each wheel, it could really be any of them.

If a front wheel is used for the spedometer, your spedo should read 58.2 at "real" 60mph. If a rear wheel is used, it should read 64.6 at "real" 60mph.

[LowGo]

I'm going to venture to guess that the speedo is based on the speed of the drive train... i.e. the rear wheels. In that case, when your speedo says 55.7 mph, you're doing 60 mph.

[da BoMM]

Again, based on the rear wheels, and the info you have is accurate, (55.7 MPH when speedo says 60) when you're going 60MPH your speedo will show about 64-65.

(MNunes already said it)

[LowGo]

Again, based on the rear wheels, and the info you have is accurate, (55.7 MPH when speedo says 60) when you're going 60MPH your speedo will show about 64-65.

(MNunes already said it)

Nope, nope nope! ;)

If he used the 1010 calculator correctly, it displays what your speedo will read when you're actually doing 60 mph (based on entering the correct stock tire size). So, in this case, with the rear wheels, his speedo would be reading 55.7 mph when he's doing 60 mph.