Increase Ground Clearance with bigger tires

[gunner.786]

Using my 2021 icon tech as a taxi and getting annoyed with the front bumper low ground clearance. Currently 205/55 r16 but has anyone put bigger tires on to increase the height? 205/60 or 205/65? 

[Paul john]

Both of those sizes would overspeed your car and therefore make the car illegal as the speedo would be reading too low for the actual speed you would be doing.

source https://tiresize.com/comparison/

[Cyker]

An alternative might be getting a lift kit; Either taller springs or inserts to raise the ride height.

I kinda want something like that for my Yaris as the rear end bottoms out quite nastily if the car and boot are full!! I swear someone put the springs for the non-hybrid version in it or something as it bottoms out much easier than I'd expect!

 

[TonyHSD]

That with the tyres sizes is totally wrong to do. They may not even fit or scrape into something. You can do suspension modification, springs from trek which are 2cm longer. 

[Red_Corolla]

205/60 would result in a 3% increase in wheel circumference.  It's well within the margin of error that the speedo has if my particular car is anything to go by. It's just not a good idea to overfill the wheel arches like that - they were designed to give clearance for a certain wheel diameter and no bigger.  All models will have about the same overall wheel size even though the diameter of the rim diameter varies.

[Mojo1010]

Does it scrapped some humps? My Yaris is 195/55/16 and hasn't scrape any humps etc. Your size tyres are the best value size, I would like that on my car. Maybe add 1-2 psi to the tyre. Other sizes may not comform to odo speed law. 

[TonyHSD]

Corolla has low front bumper and lip which results scrape off any incline roads, some speed bumps, ferry loading, hilly driveways. That’s totally normal. Many cars are like that. Tyres will do very little to increase that height. Only trek suspension will do. 2023 -> all Corolla comes with 2cm increased ground clearance but they still have low front bumper or as known approach angle. Yaris , Yaris cross and Aygo cross plus rav4 are much better cars in terms of these.
I think Yaris cross is the best small suv and has the characteristics of a true off roader , the perfect English city car designed with central London driving in mind 🫢🏁👌

[oldcodger]

Doubt doing any of the above would  be considered acceptable by your insurers and if you did not tell them you had done such modifications it could invalidate any insurance claim ?

Also wonder if  such mods would be rejected by the detailed MOT taxis must go through ?

[Talking Hoarse]

Excellent question.  As pointed out the lower part of the front valance /bumper is vulnerable as it is so low.  I had a minor squabble with my garage who scraped the car on a kerb (taking it to their car wash after service), but they did repair it nicely so I will go back to them.   Also, my car seems quite low slung - with little ground clearance.  This may be exacerbated by the longer wheelbase of a TS when going over bumps.  I have not grounded my car yet - and do not intend to - but have to take great care when driving on tracks or rutted roads.

The idea of retro fitting Trek spec springs is attractive.  Presuming the dampers etc are all same.  Does anyone know what else is involved apart from wheel align after?       

[Red_Corolla]

The only time I've scraped mine is when visiting a house with a very steeply inclined driveway and I attempted to reverse up it. The vast majority of the time, it's fine and so I'm happy to live with it. More ground clearance is never a good thing until you actually need it, which is what made the old Citroen designs so wonderfully practical, if not the most cheap or reliable.

For those with a pre-facelift that  are having a tougher challenge with the ride height than myself, I wonder if it would be worth looking into retrofitting the revised suspension components? I expect changing hub assemblies etc. would be cost-prohibitive, but maybe they're just different springs & struts?

[TonyHSD]

It might be worth it for some Corolla owners to retro fit revised suspension struts and springs or those from trek spec models. It may not even be needed anything else. 
We need someone with access to Toyota parts catalog or Toyota spares program to take the shocks and springs original numbers to confirm similarly and differences. See the prices and what exactly will be needed, it could just be shocks and springs or just springs. 2 cm difference on paper it’s nothing but in real world could make the car more driver friendly. 

[APS]

On 8/16/2024 at 10:25 PM, gunner.786 said:

Currently 205/55 r16 but has anyone put bigger tires on to increase the height? 205/60 or 205/65? 

You'd need to find a pair of wheels that size to test to truly know. They may rub on the plastic wheel arch liner in the rear. Also, the increase in ground clearance would be fairly small. I think the idea about fitting the Trek version suspension parts would be worth exploring. Or just look for a Trek spec car. 

[AndrueC]

On 8/19/2024 at 1:15 PM, Red_Corolla said:

The only time I've scraped mine is when visiting a house with a very steeply inclined driveway and I attempted to reverse up it. The vast majority of the time, it's fine and so I'm happy to live with it.

Same here. The only time I've scraped mine was when parking at a local golf course which had unusually deep and raised walkways between the bays. Even then it was arguably my fault for driving too far forward.

I've never had a problem with speed bumps even the ones at my own golf club which I've heard/seen catch other vehicles.

[Cyker]

I'd kill... well maybe not kill but gently injure, for some more ground clearance in my Mk4!

I swear they used the same rear springs in the hybrid as they do in the normal Mk4s without taking into account the extra weight of the traction Battery, as it seems to sit very low at the back. When we're 5-up with gear, the rear bottoms out disturbingly easily just going over a fairly average speed hump  

 

[Red_Corolla]

14 minutes ago, Cyker said:

I'd kill... well maybe not kill but gently injure, for some more ground clearance in my Mk4!

I swear they used the same rear springs in the hybrid as they do in the normal Mk4s without taking into account the extra weight of the traction battery, as it seems to sit very low at the back. When we're 5-up with gear, the rear bottoms out disturbingly easily just going over a fairly average speed hump  

 

These tyres should sort it

[Cyker]

But officer the speedo shows I was doing 30mph!  

[Chainbreaker]

It would be worthwhile pointing out that all facelift models have a 20mm lift in ride height compared to the pre facelift cars (with the exception of the trek).

This makes me think they've all been fitted with the trek suspension now but can't confirm this. All I can say is I've never had any worries with ground clearance and I take mines on forest tracks occasionally. Who needs an SUV?

 

[APS]

15 hours ago, Cyker said:

they used the same rear springs in the hybrid as they do in the normal Mk4s without taking into account the extra weight of the traction battery

Could be deliberate to retain grip in the rear. Well, that's me wishfully thinking they test and consider these things on ever single model and combination anyway 🙂 

[AisinW]

On 8/16/2024 at 11:25 PM, gunner.786 said:

Using my 2021 icon tech as a taxi and getting annoyed with the front bumper low ground clearance. Currently 205/55 r16 but has anyone put bigger tires on to increase the height? 205/60 or 205/65? 

If u live in a country that does not require MOT, you can easily install a new set with 205/60R16. I used to do that back then in FL. It gives higher ride, more comfortable, but slower acceleration. typical speedometer in Toyota is 5-10% faster than actual speed, so your speedometer is still slower than actual speed even with 205/60R16

[Heidfirst]

3 hours ago, AisinW said:

If u live in a country that does not require MOT, you can easily install a new set with 205/60R16. I used to do that back then in FL. It gives higher ride, more comfortable, but slower acceleration. typical speedometer in Toyota is 5-10% faster than actual speed, so your speedometer is still slower than actual speed even with 205/60R16

but in the UK it's illegal for a car speedo to underread which is why manufacturers all leave a margin (my experience is that Toyota is ~6-7%). There are calculators that will tell you how much a speedo will change by a tyre size/profile change. Given my experience I would suggest no more than a 5% change.

[AisinW]

Yes, I know that changing tire sizes is not legal in most states/countries, or kingdoms, but it has almost no problems or danger. 205/60R16, 215/55R16, 235/45R17, or 225/50R17 are still considered to be safe without any modification but not legal. The same exact thing with the dangerously dim headlight on the Auris2 with a halogen single bulb on projector headlights.Some still use bright LED projector headlights, although not legal, to be safer and more comfortable driving at night with brighter, high quality LED bulbs. the cut off in projector headlights is very sharp, no problem with glare. It is just to complicated to make special regulations in parlement/gov. 

[Red_Corolla]

17 hours ago, Heidfirst said:

but in the UK it's illegal for a car speedo to underread which is why manufacturers all leave a margin (my experience is that Toyota is ~6-7%). There are calculators that will tell you how much a speedo will change by a tyre size/profile change. Given my experience I would suggest no more than a 5% change.

3% as per my earlier post. 😇 All you have to do is work out the difference in circumference.