RX450h tyres

[Rickenbacker Al]

Hi, been reading something a little disturbing on the internet about tyre wear in relation to 'automatically-engaged 4WD systems' - specifically, the need to ensure similar tread depth front to rear in order to avoid breaking the 4WD system.  The item referred specially to the Kia Sportage - does anyone know if this advice also applies to my recently-acquired RX450h?

[olliesgrandad]

No it isn't an issue as far as I understand it, the 4wd system is different to a conventional system having the 2 separate electric motors. 

 

[Gliderpilot]

The majority of all driving in the RX400h and 450h is done in front wheel drive only, the rear motor only cuts in when the car thinks it's needed, the rear motor also regenerates to charge the HV Battery during braking. There is no centre diff or front to rear prop shaft to bother the difference in wheel speed front to rear. My local garage got bought out so when ~I took mine for its MOT the tester had not come across a hybrid before so as well as trying to test the emissions which he couldn't as you can't rev the engine, he was reluctant to use the brake efficiency rolling road, thinking it would damage the "centre diff". 

[Rickenbacker Al]

Thanks for your replies - v much appreciated.  Apologies - I meant to post a link to the item which gave rise to my query: https://www.honestjohn.co.uk/askhj/answer/122681/we-had-the-front-tyres-on-our-sportage-replaced-and-kia-says-this-has-broken-the-four-wheel-drive-system-

[olliesgrandad]

On 5/1/2019 at 6:02 PM, Rickenbacker Al said:

Thanks for your replies - v much appreciated.  Apologies - I meant to post a link to the item which gave rise to my query: https://www.honestjohn.co.uk/askhj/answer/122681/we-had-the-front-tyres-on-our-sportage-replaced-and-kia-says-this-has-broken-the-four-wheel-drive-system-

I was talking to an acquaintance on Friday whose boss has a 3 years old Porsche Macan. That is on its third transfer box and a fourth is looming.....about to get rid of it before warranty expires.