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shogunswb

Tyres

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I took my sons base IQ for a spin the other day & whilst driving quite spiritly I braked quite hard from about 60ish whilst still cornering slightly & was very surprised when the back stepped out quite violently even though the ESP was switched on. I have noticed on other occasions that it does squirm quite a lot if braking from high speed in a straight line.

The tyres are at the correct pressure but it is still on its first set of Bridgestone Ecopia EP25 tyres that can as standard on the car.

I'm not a great fan of Bridgestone & was wondering what tyres other IQ owners have replaced them with & if they are any better?

The other thing I was thinking of was replacing them with 185/60/15's to give a little better stability & was also wondering if anyone had gone down this route.

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I have 215 x18x35 on mine and lowered. Handling is out of this world

David

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Whilst I'm sure he would love to do this he only passed his test Monday & as I'm paying for the insurance (and everything else) that ain't happening but I know what you mean.

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I'm still running the Bridgstone Ecopia B250 in the 16" size and grip levels are dubious. I have slipped a few times in the wet and wheel spinning is very easily achieved. I guess a narrow tyre, hard compound and a light car is the reason.

I'm running them for the summer then am going to change wheels to 205/45 17 size and I'm going for Toyo T1-R tyres. I have tried them on my other car with 450bhp and they keep that on the road surprisingly well. :)

Craig.

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Thanks Craig.

I bought him the car because it was about the only small car that came with ESP as standard + all the other safety features & hopefully it would last him for a few years with minimal cost whilst in university, so yes I'm sure larger wheels & much wider tyres are on the cards but for the short term standard wheels & maybe slightly wider, better tyres are about the only option.

Having used the same type of tyre on different cars I know that a tyre that works really well one one car can be virtually useless on something else.

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Just a thought - could there have been some diesel or similar on the road surface, which may have been partly responsible for the back end stepping out.

From an Excel spreadsheet I have showing Toyota OE tyre fitments on new vehicles 2008-13, Toyota also fit the Bridgestone B250 and Yokohama S70 to the 1 litre IQ as OE.

Fitting 185/60/15's may make the speedo under-read slightly at 70. In the most recent Which? test on car tyres the Best Buy tyres for this size were (in descending order): Continental ContiPremiumContact 5, Goodyear Efficient Grip Performance and Michelin Energy Saver +. Three 'Don't Buys' due to their poor wet grip were Kleber Dynaxer HP3, Marangoni Verso and Sailun Attrezza SH402.

For 185/65/15's the Best Buys were Michelin Energy Saver and Pirelli Cinturato P6.

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Welcome to the forum.

Is it a used iQ with tyres that are run in, or a new car with Green/New tyres without a few miles on them?

It is a short wheelbase car with electric assist steering, Esp, brake assist etc etc.

The standard tyres actually behave pretty well, in wet a snow covered roads.

Maybe some driver adaptation to the car and difference of it from other cars being driven is required,

ie

Drive the car as is, and to the conditions rather trying to mod the car to suit the driving style.

it will be perfect probably with your son being a new driver.

george

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Do you know how wide the standard rims are on the 15" wheels?

205/55 15 are only 2mm smaller diameter than the standard 175/65 15 and there is lots of choice in that size but you may well require a wider wheel for them.

Craig.

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It's a 59 car with 6k of very gentle driving on it when we got it. The road surface was clean & dry & it was definitely the tyre, mainly the tyre wall causing the problem (I also accept ultimately I was the cause of the situation).

The 185 tyre would cause a slight difference in the speedo but as has a tendency to over read should be ok & I don't really want to fit larger wheels.

My main concern is that my son will very soon start to explore what he & the car can do & whilst I'm quite used to throwing a car around on a track & in the woods, a novice driver would not have caught the slide I experienced in the IQ.

Tyres in my opinion are the biggest safety feature on a car & finding the right tyre/car combo can save an awful lot of problems.

Michelins have always had good grip & decent sidewalls but I had a problem with them delaminating on a Renault 5 1.1L so I'm a little wary of them. Conti's are hard & almost dangerous in the wet on my MG ZR 160. Not really had much to do with Goodyears but I do like Yokohama so maybe they are the way to go.

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?? What have you set the tyre pressures at?

Going to a 16" wheel is not going to make that much difference on the Tyre Profile/Side wall height,

its 15" wheels on the iQ,

and 16" on iQ2 & iQ3 as standard.

17" rims will give you lower profile tyres if thats what is going to give the handling you are after, more than just fitting a less 'ECO' type tyre compound as is fitted.

(low rolling resistance, which actually is the same as saying, not much grip.)

I must suggest your slide you had to catch is not normal behaviour for a iQ being driven sportingly on public highways,

(well maybe it is when braking mid corner at around 60 mph, dependent on the road surface and tyre pressure)

best check things out on the car.

(I drive offroad quickly and on road with verve in different cars,

an iQ can be driven like an original mini,

ie keep the throttle down in corners and expect to be in control,

braking in corners or on different road surfaces with Electrics switched on can take that control away from the drivers control), yes a safety feature, but then lifting off and slowing down if the car is at its limits is also a safety feature on all cars.

One thing to check with the car because it is a 59 plate is that it has had the re-call work done already when in the previous owners possession..

*Cheap, since the RE-Call work costs nothing to you, if it has not been carried out already.*

It should possibly have had the steering done, that caused a braking problem before the fix was done,

and an ecu update and the brake pipe recall which would have had the brake fluid changed.

(the brake fluid is due to be changed again probably.)

iQ's THAT WERE FIRST SHOWING PROBLEMS BEFORE BRAKE RECALLS, HAD THE BRAKES BEHAVING FUNNILY ON ROUGH ROAD SURFACES AND THE LIKES, HENCE THE NEED FOR THE ECU UPGRADE.

Handling really is not a problem on an iQ, if you suspect yours is not just as it should be you maybe want

another iQ driver to try yours,

or go roadtest a couple of other iQs if you have not already.

Fit as good tyres as the budget allows, but maybe the suspension is needing looked at.

Maybe the car has just had such an easy life having done only 6.000 miles.

The springs are pretty much unstressed, or actually the dampers could be shot even tho the cars has hardly done any miles.

this all needs considered and looked at.

Look closely at those tyres, low mileage but sitting square wheels if not in a garage out of the sun and weather

is not great for tyres.

And maybe go try driving the car in your sporting manner 'with the electrics switched off,'

Hold in the Button for over 3 seconds and switch it off.

The car handles well. or should on dry good surfaces.

But importantly check the RE-call work has been done and inspect again those Tyres, Discs, Pads and see that they are all perfect.

http://www.kouki.co.uk/utilities/visual-tyre-size-calculator

http://www.fensport.co.uk

http://www.fensport.co.uk/Parts/Model_97/Category_2

http://www.fensport.co.uk/FensportCars/iQ3.aspx

http://www.camskill.co.uk

george

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Hi George

I must admit I didn't know about the brake pipe recall but I'll check. What's the edu update for?

I bought it from a Toyota main dealer who had looked after it from new & was owned by a little old lady who used it for shopping once a fortnight by the looks of things.

The tyres are in good condition & I did try upping the tyre pressure slightly from 2.3b - 2.4b but made no difference & as the centre of the tyre is wearing more than the outside I lowered it down again.

The handling otherwise is fine, it's just under heavy breaking it's a concern.

It first came to light when I was trying to explain to my son about keeping the clutch engaged until the last second when braking heavily & showing him the difference in the stopping distance with the clutch engaged & then disengaged when I braked & was quite surprised how much steering input was required to keep it in a straight line.

It's very similar to my Mitsubishi Shogun. When I got it it's rear tyres were nearly new mid range road tyres but it move about all over the place. Changed all 4 for Yokohama AT's & it's completely transformed the handling.

Thanks for the links

Bob

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I drive a Jimny Automatic as a daily driver, onroad and another one off road so know a little about tyres and loss of adhesion regarding tyres. (rear wheel drive)

My fun car is a FWD Twincharger with DSG, which can spin tyres by just thinking about it.

The iQ is a pretty nice car without power that can give loads of fun and safety.

http://www.dft.gov.uk/vosa/apps/recalls/default.asp?tx=VOSA

RE-Calls.

Best check that out.

Throttle pedal, Steering was changed, sensor, and the ECU update was to rectify the fault in the Braking System.

Electrics kicking in when they should not have, upset by rough road surfaces even at low speeds.

The Brake Pipe recall was a safety matter due to some manufacturing of brake pipes with contamination.

(the brake system should have been flushed, so that a brake fluid change been done.)

Should be easy to check your car out to see it has been done.

Less easy to check it was done correctly.

Maybe go to another Dealership to ask,

it will show on the Toyota Records if done.

george

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Hi Bob

Have you resolved your problem? If so, what tyres did you finally put on your son's IQ?

I'm really happy with my liitle IQ, but I've to say that the road hadling isn't great (especially if I brake when cornering)

I don't know if changing the tyres (I've heared that Dunlop SP sport are great) would resolve this, or if I need to Install firmer springs.

I've asked a dealer in Paris ( very very bad service by the way) and the only thing he suggested is to change my tyres ( mine are like new)...Because they have a promotional offer on Bridgestone tyres at the moment!! Useless!!

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When I first got my Iq3 (which had 52k but a gentle lady owner) I got into a skid when I had to brake hard for the first time. I had my mate at Hiq check it out, and he thought that although the discs and pads were ok, they had glazed due to lack of use. He suggested several heavy applications of the brakes (when safe) which has cured the problem. Hope yours is that simple. Cheers Colin

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Thanks Colin!

I also hope it's that simple! Anyway I'm going to give it a try and I'll keep you updated!!

Cheers

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There were some problems with underuse of the rear discs so had them changed but made little difference.

Found a couple of part worn Dunlop SP sport fast response tyres on Ebay so gave them a go on the front & the car was immediately much much better in the wet, dry & braking. Found another couple, stuck them on the back & it was better again.

I know I found these on Ebay but I never use cheap brand tyres as in my opinion they are the biggest safety feature on your vehicle. Having said that just because a particular tyre works on one car doesn't mean it will work on a different car so you have to look at how a tyre performs in different sizes & on different cars.

I wouldn't change the springs as it's stiff enough as it is. Good shock absorbers would definitely give it a little more grip but I think if you change the tyres for Dunlop's you will be surprised at the difference.

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Thanks shogunswb for the reply!

I did 40 miles with the car yesterday and tried several hard applications on the brakes, I haven't noticed any changes so far.

So, fitting the dunlop fast response tyres would be my next step.

Did you keep the standart size? (175/65/15) ... I have found a set of yaris wheels with the same dimension, the guy has just to confirm if the dunlop tyres are the SP sport ones.

I've asked a dealer if I can fit a Yaris tyres on an Iq, but they don't know :( I beleive it shouldn't be a problem as they're all 4x100

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I kept the original size because the tyres in that size have the best rating for wet & braking. If you choose a different size they do not perform as well, in some cases they go from an A rating to a C if memory serves me right.

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Ok, thanks for the advice Bob!

I'm gonna stick to the original size then, I don't really mind if they're skiny...As long as they're safe.

They guy who sells the set of dunlop still haven't replied to my message :( ...But anyway, if he doesn't, I'll always find another set later on. The most important thing to me now, is to know what tyres fit the IQ best to be safe.

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Normally with my cars I manage to scrub the outside edge of the tyres whilst cornering even on one car which had wide 45 profile tyres, on what was a relatively light hatchback but there is virtually no sign of this on the IQ with Dunlops which is a first.

Just so that we are talking about the same tyres, link below to some new ones on Ebay, pretty good price for 4 new ones as well.

http://www.ebay.co.uk/itm/4-summer-tyres-175-65-R15-84H-DUNLOP-Fast-Response-/271904913263?pt=LH_DefaultDomain_3&fits=Tyre+Width%3A175%7CAspect+Ratio%3A65%7CRim+Diameter%3A15&hash=item3f4ecbb76f

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Thanks for the link shogunswb ;)

I'm in France but I've found some dunlop tyres at a very good price as well (about € 60 each) + fitting

Of course, I would have prefered a set of wheels (rims with tyres) because my tyres are brand new, and it's a pity to get of them.

The second reason is, if the problem persists, it might be coming from something else ( the brakes for instance )

The more I drive the car, the more I have the feeling that the brakes are really strange... As if there's a problem with their distribution.

When cornering (without breaking) the car's road handling is really amazing, but as soon as I apply the brakes, the car becomes immediately unsteady, and if I apply firmy, the car just gets into a skid (especially the rear)... So now I'm wondering if I need to change a part (heard of master cylinders problem on some toyota) in the braking system, or if I need to change the tyres...Or both :(

The guy who sells the full set of wheels is coming back from holiday only in mid August, so I'll see if I can sort this out before.

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Not to start this thread up but did you resolve your issues when breaking? I am on stock wheels and tyres and have found cornering fine until breaking where a person has walked out into the road from between cars (myself at 20-25mph) and hitting the brakes for the rear to snake out. I am waiting for the TRD rear sway to install as didn't want to lower tbh but if nothing else helps then may do? Tyres are Bridgestone .

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No, unfortunately I didn't resolve my problem. I've contacted several dealers but they all said that the IQ is designed like that. I just have to be careful when cornering and braking ;(

I managed to get a set of Hankook tyres (standart size) for a good price, but even with different tyres, the problem persists, so you're right in installing a rear sway bar as I think it's problem of "transfer of mass"

Please let me know if you find a solution.

It would also be interesting to know, if the Aston Martin Cygnet has the same problem (which I doubt) ...And if not, is the suspension different?

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Guys, I have found this video (sorry it's in dutch) ...But it speaks by itself. At 1'09 you can see the little IQ sliding from right to left on wet surface ;((

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