Low Resistance Tyres

Technical discussion on converting internal combustion to electric
Post Reply
Barry Murfett
Noobie
Posts: 26
Joined: Fri, 08 Feb 2008, 00:05
Real Name: Barry Murfett
Location: Maldon
AIM: 7 Boundary Rd
Contact:

Low Resistance Tyres

Post by Barry Murfett » Wed, 16 Jan 2013, 19:55

I will needing some new tyres on the front of my electric BM soon. I've heard a lot about low rolling resistance tyres and the ones on the back are labled as such. But, is one tyre better than another and is it just some writting on the side wall the keep the greenies happy?

Is there a measurment for the rolling resistance? A figure so I can compare one brand agaisnt another? Is there something I can do to comapre brands?

Can anybody suggest a particular brand that they know has a 'low rolling resistance' ?

User avatar
Johny
Senior Member
Posts: 3691
Joined: Mon, 23 Jun 2008, 16:26
Real Name: John Wright
Location: Melbourne
Contact:

Low Resistance Tyres

Post by Johny » Wed, 16 Jan 2013, 20:09

I had this quandry with my EV. I finally bought Hankook Enfren LRR tyres but really just because they were the only ones that came in 13 inch rim size and that I had read anything independent about (good grip in wet and good wear).
This is a page I stumbled across during my net travels. Maybe helpful.
http://ecomodder.com/forum/showthread.p ... -2813.html

JFK
Noobie
Posts: 4
Joined: Thu, 10 Jan 2013, 00:25
Real Name: John
Location: Perth

Low Resistance Tyres

Post by JFK » Wed, 16 Jan 2013, 23:40

Try Bridgestone. My Prius has Bridgestone Ecopia LRR tyres.

User avatar
acmotor
Senior Member
Posts: 3592
Joined: Thu, 26 Apr 2007, 03:30
Real Name: Tuarn
Location: Perth,Australia

Low Resistance Tyres

Post by acmotor » Thu, 17 Jan 2013, 01:26

My i runs Dunlop enasave 2030's.
Mitsubishi iMiEV original equipment.
I think that Mitsubishi would have done their homework. (at least in Japan)

Inflation, and wheel alignment (front AND rear) would have a lot to do with RR as well.

Image
iMiEV MY12     102,980km in pure Electric and loving it !

User avatar
woody
Senior Member
Posts: 1707
Joined: Sat, 21 Jun 2008, 02:03
Real Name: Anthony Wood
Location: Mt Colah

Low Resistance Tyres

Post by woody » Thu, 17 Jan 2013, 02:43

There is a coefficient of rolling resistance which is the proportion of the downward force (load) which opposes any rolling movement. Somewhere around 0.012 for average tyres from memory. I.E. 800kg ~ 8000N of car will require 96N of force to keep it rolling. This is around the same force as needed to overcome air resistance at city speed (50kph) so a big change in RR will save you lots of energy.
Planned EV: '63 Cortina using AC and LiFePO4 Battery Pack

User avatar
Richo
Senior Member
Posts: 3314
Joined: Mon, 16 Jun 2008, 00:19
Real Name: Richard
Location: Perth, WA

Low Resistance Tyres

Post by Richo » Thu, 17 Jan 2013, 20:59

If you slide off the road into a ditch it will save even more energy. Image
Help prevent road rage - get outta my way! Blasphemy is a swear word. Magnetic North is a south Pole.

User avatar
woody
Senior Member
Posts: 1707
Joined: Sat, 21 Jun 2008, 02:03
Real Name: Anthony Wood
Location: Mt Colah

Low Resistance Tyres

Post by woody » Thu, 17 Jan 2013, 22:30

Good point - a contact patch on a flat road = tyre deformation = energy use.

I think the LRR tyres deform less but also "rebound" i.e. some of the energy used to deform the tyres is stored and given back when the deformation ceases / tyre rolls around a bit further.
Planned EV: '63 Cortina using AC and LiFePO4 Battery Pack

Post Reply