Tyre Difference

[LittleM@n]

I have just a little question: What is the difference between a 175/65R14 standard tyre+steel rim, and a 195/50R15 tyre+aluminium wheel?

Will the time from 0-60 mph increase? And the 60-0 decrease?

[reece]

Speeo reading with non stock tyre is 1.2% too fast.

When your speedo reads 60mph, you are actually traveling 59.3mph.

175/65-14;

Sidewall = 4.5in. Radius = 11.5in. Diameter = 23.0in. Circumference = 72.1in. Revs/Mile = 879. Difference = 0.0%

195/50-15;

Sidewall = 3.8in. Radius = 11.3in. Diameter = 22.7in. Circumference = 71.2in. Revs/Mile = 889. Difference = -1.2%

[LittleM@n]

Ok, i know that.

I'm not refering to the speedo, I'm refering in real time, if the time increase; and the fuel consumption will be bigger?

Anyway, tnx 4 answer

[reece]

Your question was the difference between a standard tyre and rim and an after market one.

With the sizes you have put and the answer I have given, you will be able to work out that in real time it will take you longer to reach 60mph.

To save you time I have done a rough calculation give or take .00001 of a %

The time it will take to get from 59.3mph to 60mph in real time (0.7 of a mile per hour) with tyre sizes you have mentioned plus the equation of the weight of your vehicle (assuming you are on your own in the car and carrying no luggage) and weight an average of 75kg with 20 litres of fuel on board and with the tyre pressures set correctly thus reducing drag, works out at 0.0023 of a second which equates to 0.000098th of a litre of petrol.

This obviously isn’t taking into account air density, altitude and air temperature.

If you provide me with your location I can work out the height above sea level and work out the atmospheric pressure reading, pressure trend, and the wind direction on the particular day you perform your test.

Also you can provide me with the cost per litre of 95RON of unleaded, I can tell you how much in hard earned cash it would cost you to accelerate the 0.7mph

[Al J]

Slow night, Reece?

I'm pretty certain an increase in overall diameter reduces acceleration though there are so many other factors to take into account, rotational mass being just one of them.

To be honest, you'd hardly notice the difference in everyday life which is, I think, the point to which Reece was intimating. ;)

[DaveSR]

Haha Reece you are so funny ...... TOC would be boring if you wasn't here !

To make it simple and to briefly summarise Reeces answer:

If you increase the tyre size it will decrease your 0 - 60 time, and as the wheel needs to turn more to complete one full cycle you will therefore be using more petrol.

But with only a small difference in size I doubt it will make much diffence at all ...... I guess only the stig could prove it ;)

[reece]

Haha Reece you are so funny ...... TOC would be boring if you wasn't here !

I keep telling myself that :D

I don’t know what’s worse... the stupid question or me taking half an hour of my life thinking up a witty & sarcastic reply

[Al J]

Oh it was worth it, trust me.

[LittleM@n]

Ok, you convince me :), the 195 is better

Nice answer...I really appreciate your interes :D

[bigsmall]

Big wheels look nicer and corner better. The trade off is a harsher ride and slightly lower mpg..