Bigger wheels increase milleage faster than smaller wheels

[Kelpie]

Hi Bros,

 

Do you need to find tune the ECU if you use a bigger set of wheels? A friend of mine realised that after using 17" wheels for a while, his mileage count increase relatively rapidly. Once he has switched back to 15" wheels, he found that the milegae meter increase at a slow rate. Is there any truth in this?

 

Regards,

[Vit4wd]

Yr friend prob did a wrong upgrade.

[Toalson]

The OD for the new tyres were prolly much bigger than original. If OD the same than its the weight and grippyness of the bigger tires.

[Mok_]

I'm sure you meant Odometer. It depends on the size the tyre, not the rim size.

 

If you are using an oversized tyre (bigger OD), the odometer will be increasing at a slower rate than stock. If you undersized, the odometer will be increasing at a higher rate than stock.

[Mage]

assuming same distance travelled ..shoudlnt bigger wheels translate to lesser mileage instead of higher or more mileage on the odo?

[Stivo]

not really!! it depends if you are on the freeway or from a set of lights to the other... do take note that, it actually take more for the wheels to turn as compared to having a smaller one... by saying that... wheels needs to turn lesser to reach your destination!!!

[Somebody]

from wahat i can understand:

 

assuming same distance:

 

bigger wheels = less wheel revolution = less mileage on the odometer

smaller wheels = more revolutions = more mileage on the odometer...

[Mage]

sorry ..i dun understand what u're saying ... However, "Somebody"'s post is exactly wat i'm trying to say in my earlier post ..

Edited June 27, 2006 by Mage

[Stivo]

yup!! if you are asking about which fc is better then i can't give you an exact answer cos there are too many variants!!

[Mage]

bro .. read properly .. i mentioned odo, how come FC come into the picture?

[Stivo]

sorry mage :) ... my boss is actually walking here and there so i juz type whatever is coming... hehehhe!!!

 

please do find research on wheel size, PCD, clearance, tyres sizes, for example... if your ride right now has 195/55/15 and you wanna go 16". If you think that you can go for 195/55/16 then you are wrong... your speedo will be out by 4.3% meaning 100km/h = 104.3km/h... the closest bet will be changing 205/45/16, at least you are only 0.8% slower, meaning 100km/h=99.2km/h

 

Of cos, it will read lesser on the odometer as compared to a smaller wheel sizes as right now it takes lesser rev/km....

[Stivo]

thanks for your comment :)

[Skyline_wj]

bro,which one will cause fc suffer?? thankx

 

the closest bet will be changing 205/45/16, at least you are only 0.8% slower, meaning 100km/h=99.2km/h

@ means u travel less???

 

If you think that you can go for 195/55/16 then you are wrong... your speedo will be out by 4.3% meaning 100km/h = 104.3km/h

@means u travel more??? save fc??

Edited June 27, 2006 by Skyline_wj

[Genie47]

Doesn't happen that way. The odo takes its reading from the VSS. Not from the tires. So mileage covered is not dependant on total circumference of the wheels.

[Mok_]

Odometer measures distance. Vehicle Speed Sensor measures speed. I believe both the vehicle speed and distance covered (odometer reading) are derived from the rotation of the drive shaft assuming a certain tyre diameter.

 

I do not think that any road car uses an accelerometer to compute the actual speed and distance covered. It would be too complicated with varying road gradient.

[Genie47]

They do. The distance covered is derived from the VSS. It is very obvious in the cars with the trip computer or the fuel economy meter. All these take their readings from the VSS.

[Mok_]

What did they do? Use an accelerometer? Where does the VSS get it's reading from?

 

edited grammatical error...

Edited June 28, 2006 by Mok_

[Genie47]

Obviously the transmission output. So the wheels circumference doesn't matter. With the advent of these electronics, I don't think the odo gets data physically and directly from the transmission anymore ala worm gears and stuff. The VSS doubles as the pickup for the odo as well as the speedometer.

 

Then again the system is damn complicated. The VSS is needed for the cycling of the brakes in ABS in ABS equipped cars. If it is faulty, you bet the CEL will nag you to visit the tech.

 

So even an OBDII fault tells you the VSS is screwed which means the odo is screwed as well.

 

Its so much simpler with the good ol' carburetted days.