iMiEV tyre wear status

Post by **acmotor** » Mon, 08 Jul 2013, 04:55

bga and I did a quick check the other day of iMiEV tyre wear.

That inspired me to record some measurements for other i owners to compare.

At 28,097km in my i the tyre treads measure :-
depths in mm
groove    left    2    3    right
RR        4.8    5.8   5.7   4.7
LR        4.9    5.8   5.7   4.4
RF        3.6    4.3   4.3   4.2
LF        3.5    4.6   4.7   3.8

Tread wear indicators are at 1.6mm

I run these tyres at 39psi with plenty of 100km/h 1 person work.
The tyre wear suggests tyres are not over inflated.
The side wear probably reflects my enjoyment of cornering with the i's low COG.

If other i owners can make measurements then we can get a picture of tyre wear and life expectancy.
It would be good to get a 'new' depth measurement by the same method.

Post by **Adverse Effects** » Mon, 08 Jul 2013, 06:27

i would be taking them up to 44 but you will lose a bit of comfort

Post by **acmotor** » Mon, 08 Jul 2013, 06:42

Mitsi say 36psi on the vehicle placard and I use 39psi, but yes, they are only small tyres with 1100kg vehicle so maybe going up more could be on the cards.
Ride quality would be more up to the suspension. It would be the thump of a pothole that would increase with a harder tyre ? Road (tyre) noise would drop, rolling resistance would drop and handling improve. Not that the i seems to have trouble with any of that.

Post by **Kimball** » Tue, 09 Jul 2013, 03:41

Looks like your right front is scrubbing, AC Motor, that could be the rear wheel alignment, you would expect the left front to get more wear if roads you use have a lot of camber not the right, unless you continually get crosswinds.
Main point, I got a i-MiEV on loan a year ago, the ride and handling were terrible, until I checked the tyre pressures, the highest one was 23psi.
There are reports the tyres go down, how often do you check them?
I put mine up to 38 and after 3 months they were down to 32 all round, 6 weeks later they were under 30. (Now they are back up to 38) Does this go away when the compound ages?

Post by **ZIPPIE11CAR** » Tue, 09 Jul 2013, 04:50

I'll pick up a vernier & check mine @ 1500km

Post by **acmotor** » Tue, 09 Jul 2013, 06:28

I check tyres pressures about once a week seeing as I do up to 600km a week. I also do a walk around daily. (while admiring this marvel of electrical transport

)

When I check pressures they are within a psi, but as I noted elsewhere on the forum, they are small tyres and checking the pressure drops the pressure by about 1 psi each time so put it back in !

I don't think the tyre wear shows any tow in/out/scrub anywhere.
The main message seems to be that the 39psi appears to be under inflation.
Reference to the iMiEV.com forum suggests that many folk are using 40 to 60psi (though 51psi is on tyre sidewall)

I did take note today that there are 10 roundabouts on my usual run. Most of which I 'enjoy' so that may have an affect on the left side wear of the front tyres.

I will swap the front tyres side to side and the rear tyres side to side to share the wear pattern.

Post by **g4qber** » Tue, 09 Jul 2013, 06:32

As mentioned on the mitsu sig. My pressures seem to drop. I tend to use the 36 psi recommendation

http://www.aeva.asn.au/content/tyre-pressures-drop

Post by **Kimball** » Wed, 10 Jul 2013, 04:34

Hi, AC, enjoyment of the driving experience when entering roundabouts might do it, that and hard left turns. Although I must confess the skinny fronts do not give me the confidence to chuck the i into a corner.
I usually wait until I am in a straight line before amping it, which I try to limit to once a trip. Last event was a Toyota land crusher nearly in my back seat as I tippy toed around an intersection. They really do seem to actually shrink in the rear vision mirror.

Post by **acmotor** » Wed, 10 Jul 2013, 07:42

At the 15,000km service the local mitsi dealer asked me if I wanted the tyres rotated.

I laughed and said he was welcome to try and suggested that a side to side swap was all that could be offered. They didn't do that either in the end ! (either offended or confused perhaps)

The i did come back with a 'next oil change due at 30,000km' sticker on the top inside RHS of windscreen. Oh well... I guess there is a lot that will have to change in service departments. A fair bit of retirement for one thing.

Those 145 fronts were chosen for a reason I guess. Maybe to look silly ? No, perhaps to limit power consumption by electric power steering or something. Anyway, they seem to do the job and the i is rather quick in the corners with its low COG and silent instant power. Most ICEs have to change down/kick down to exit with good power yet the EV drive train, in particular RWD, goes from controlled regen to full torque without any delay or effort. Its a driver's dream really.

Post by **g4qber** » Wed, 10 Jul 2013, 08:39

watch out for a roadworks pothole under the city west bridge

the left tyres went completely into it
will see if there is any tyre damage tomorrow or flat tyres in the next week.

Post by **acmotor** » Thu, 11 Jul 2013, 00:17

Just looking around as the replacement tyres question will come up in the future. Could be in less than 12 months....

Presently
fronts Dunlop Enasave 2030 145/65 R15
rears Dunlop Enasave 2030 175/55 R15

My local tyre shop over the phone says these are $218.70ea. F&B front and $214.30ea. F&B rear in same Dunlop 2030s. Both avail in Oz. So they are around. Would hope for a better price.

BTW, UK price is GBP 50.20 front and GBP 72.40 rear. I guess that makes up for their expensive fuel.

There is a temptation to go to 155/60 R15 on the front (not avail in 2030's though ?)
comparison here

Bridgestone ecopia isn't avail in < 175 width on web site.

Any other options ?

Post by **g4qber** » Thu, 11 Jul 2013, 05:54

Checked pressures today. 33 psi all round. Pumped back up to 36 psi.

Post by **acmotor** » Sun, 14 Jul 2013, 07:05

Just checked tyres after 2 weeks, were set at 39psi.... now 38,38,39,38.
Set them now to 40psi.

Post by **ZIPPIE11CAR** » Sun, 14 Jul 2013, 07:11

Kmart online can do the above Dunlops for $196.

http://www.ktas.com.au/tyres/vehicles-m ... miev/2012/

Post by **ZIPPIE11CAR** » Sun, 14 Jul 2013, 07:17

Here's a list from a Euro on the myimiev forum:

In europe we have more than 10 different tire brand wich fit.

Front tire : 145/65R15 72 T

http://www.allopneus.com/find?activite= ... n=e&page=1

Rear tire : 175/55R15 77 T

http://www.allopneus.com/find?activite= ... n=e&page=1

Here is a short list :

Toyo Proxes NE
Hankook K425
Vredestein Quatrac 3
Yokohama A.Drive AA01
Bridgestone B340
Bridgstone Turanza ER300
Pirelli Cinturato P6
Continental Ecocontact 3
Michelin Energy XT1
Dunlop Enasave 2030
Goodyear Vector 5

Theses size also fit SMART fortwo and forfour

Post by **ZIPPIE11CAR** » Sun, 14 Jul 2013, 07:30

http://www.toyotires.eu/tire/pattern/proxes-ne

Quote from site:

In a World first, recycled polyester fibre is used in the manufacture of the tire casing.

Post by **acmotor** » Sun, 14 Jul 2013, 07:30

What about a 155/60 R15 upgrade for the fronts ?

Post by **ZIPPIE11CAR** » Sun, 14 Jul 2013, 17:57

Put some "fats" on

Going wider doesn't necessarily mean bigger "foot print" area on the ground.
The lower profile would give a harder ride also.

Post by **acmotor** » Mon, 15 Jul 2013, 01:07

It is just a cosmetic thing perhaps.
The present fronts are smaller than some motorcycles. (well they seem that way)

The profile number (65 or 60) is a ratio to tyre width and tyre specs show the 145/65 R15 and the 155/60 R15 have the same rolling diameter, they use same rim so thus profile is the same not lower.

I'd like to know the technical reason for the size choice by Mitsi.
Was it power steering energy consumption, rolling resistance, what was laying around the lab at the time ? It appears that tyre cost was not a justification.

The tyre size must be one of the narrowest chosen for a given vehicle weight since radial tyres were invented ?

edit: not complaining, just pondering the logic.

Post by **ZIPPIE11CAR** » Mon, 15 Jul 2013, 02:03

Definitely an interesting one.
Maybe you nailed it with power steering reason.
Lower unsprung weight for handling??

Post by **ZIPPIE11CAR** » Mon, 15 Jul 2013, 02:20

Ones on the back needing to be wider due to weight?Not looking at it needing Skinnier ones on the front for any reason. Maybe if there was less load on the back they could be same size as the front ones?

Post by **Hippie403** » Mon, 15 Jul 2013, 02:26

The Rinspeed i-MiEVs have these wheels and tyres:

Front: Tyre 175/50/16 Wheel 16"/5.5"/ET 34
Back : Tyre 195/45/16 Wheel 16"/6.5"/ET 33

Make Work Japan, model schwert SC1 (SW1)

Post by **ZIPPIE11CAR** » Mon, 15 Jul 2013, 02:41

Rinspeed website has some good concepts/ideas.

I guess the 3 spoke mags are more aerodynamic than the multi spoke whilst still adding ventilation without going to a full disc on the MY12.
Wonder why the back wheels never got a wheel arch body cover for more aerodynamics? I guess to make it look "normal"

Post by **offgridQLD** » Sun, 04 Aug 2013, 23:39

Post by **unheardofinstruments** » Mon, 05 Aug 2013, 04:07

I would be interested in some data on the amount saved using low rolling resistance tyres like the ecopia etc vs normal form a real world situation, ev range should be able to be substantially improved if the spiel is real.