Excessive body roll in the Yaris Mk3.

[Mojo1010]

1 hour ago, turtle15 said:

If it is the Mk3 it must be 195/50 R16 (not 55). The Mk4 is the 195/55 R16.

And yes, if I were to replace the tires it would be because of the sidewall (lower). The tire width (at least theoretically) does not affect the body roll.

Isn't Fiesta the king of handling 😂?

As far as the Polo is concerned, here is a video showing the two side by side in the moose test (starting at 9 minutes): https://youtu.be/6KhSuheJd0A

From the video (if anything), I would even say that the Polo has more body roll.

It was a really old fiesta MK4 with 165mm tyres. Well good luck with your car, given you info on my first hand experience details of the changed I'd made. 

[YarisHybrid2016]

My wife hates my Mk.3 in turns. Mk.4 is night/day difference.

Mk.3 also likes to slide out/understeer if you're a bit sporting on roundabouts.

I have the 16" on mine.

[bathtub tom]

I've a pre-facelift MK3 and can't say I've noticed excessive body roll (since my Kia Pride, which pitched and rolled like a drunken sailor, but was so comfortable), however I've never had a car that suffers as much from side winds in my MK3 since my Hunslet Scootacar ( I wouldn't take that on motorways after my first experience).

I suspect fatter tyres would help stability, at the cost of economy?

[Max_Headroom]

28 minutes ago, turtle15 said:

If it is the Mk3 it must be 195/50 R16 (not 55). The Mk4 is the 195/55 R16.

I put my reg into the site i linked to and that's what it came back with 195/55 R16.

 

Quote

And yes, if I were to replace the tires it would be because of the sidewall (lower). The tire width (at least theoretically) does not affect the body roll.

Amen to that.

[YarisHybrid2016]

1 minute ago, Max_Headroom said:

195/55 R16

That's what mine has.

[Max_Headroom]

45 minutes ago, Cyker said:

I must say this thread is very interesting as this is the first time I've heard so many Mk3 owners complain about bodyroll!

It looks like its the pre facelift that are the ones that roll my 2019 certainly doesn't and i live in the lake district so regularly drive on twisty roads i can honestly say the Yaris is more fun to drive than the "sporty" SXI Corsa i had before it, all that did was damage your spine every time you hit a small pot hole, way too firm for me.

[Max_Headroom]

10 minutes ago, YarisHybrid2016 said:

That's what mine has.

Thanks @YarisHybrid2016 

Someone posted on page one (see below) that mine must have 50 profile but the site i linked to said 55 i was sure it was 55.

 

Quote

If it is the Mk3 it must be 195/50 R16 (not 55). The Mk4 is the 195/55 R16.

 

[turtle15]

14 minutes ago, Max_Headroom said:

It looks like its the pre facelift that are the ones that roll my 2019 certainly doesn't and i live in the lake district so regularly drive on twisty roads i can honestly say the Yaris is more fun to drive than the "sporty" SXI Corsa i had before it, all that did was damage your spine every time you hit a small pot hole, way too firm for me.

Theoretically the pre-facelift ones would have the lowest body roll, considering they have the stiffest suspension...

20 minutes ago, YarisHybrid2016 said:

That's what mine has.

Very strange, does it also appear in the owner's manual? I have only seen Mk3's with 195/50 R16. Unless it's a UK specific size....

24 minutes ago, bathtub tom said:

I've a pre-facelift MK3 and can't say I've noticed excessive body roll (since my Kia Pride, which pitched and rolled like a drunken sailor, but was so comfortable), however I've never had a car that suffers as much from side winds in my MK3 since my Hunslet Scootacar ( I wouldn't take that on motorways after my first experience).

And there is that too. I don't mind it but I admit it's scary.

[Cyker]

29 minutes ago, Mojo1010 said:

It was a really old fiesta MK4 with 165mm tyres. Well good luck with your car, given you info on my first hand experience details of the changed I'd made. 

Ahh, my first car was a 1.3L poverty spec one of those! I feel the tyres were wider as my Mk1 Yaris' tyres looked comedically narrow by comparison. The Fiesta had very nice handling and incredible cornering grip right before it suddenly let go and threw you into a hedge  

That car is partly responsible for my current minimal-braking driving style as, despite having a 1.3L engine, it was so gutless I had to devise ways of conserving momentum at all times because it took so long to accelerate! I think the 1.0L Aygo has more torque and power than it did!!

It's also the car that, after being stuck in it on the M1 while they were widening it in high summer, made me swear to myself that my next car would have aircon  

Most people have fond memories of their first car... I do not!!  

 

[turtle15]

1 hour ago, Cyker said:

Eh, that doesn't make sense to me - The squishier a tyre, the higher the rolling resistance, as that deformation soaks up energy, so they make them harder and less squishy to reduce rolling resistance.

I'm pretty sure I saw the explanation I gave somewhere in a credible source (press material, perhaps?). Anyway, the extremely soft sidewalls of the Continental EcoContact6 (the king of fuel economy?) seem to back up my explanation. However, I could be wrong...

1 hour ago, Cyker said:

This is provable just with tyre pressures - Run a tyre at 20psi and see how it rolls, then inflate it to 40psi and see how it rolls - The 40psi one will roll much better, and is partly why I err to higher pressures.

Is it not because with the increased pressure the contact patch of the tire has reduced considerably?

[TonyHSD]

All mk3 Yaris body roll more than Yaris mk4 and it’s because of three major factors: 

Centre of gravity

tyre tracks

and chassis stiffness 

Mk4 has wider track front and rear , lower centre of gravity, stiffer and shorter body . Add the wider tyres with low profile tyres and dual action shock absorbers and you have a hybrid that drives like fiesta.
All of that comes at a cost of less headroom and legroom, but much better handling. The Yaris GRMN are even on the rolling side if you ask me and I could see that when car been pushed in corners. 

The roof Line aka centre of gravity dictates handling. 
Yes, lower profile 195/50 16 tyres will improve your experience but don’t expect miracles. 👍

[TonyHSD]

27 minutes ago, turtle15 said:

I'm pretty sure I saw the explanation I gave somewhere in a credible source (press material, perhaps?). Anyway, the extremely soft sidewalls of the Continental EcoContact6 (the king of fuel economy?) seem to back up my explanation. However, I could be wrong...

Is it not because with the increased pressure the contact patch of the tire has reduced considerably?

Softer tyres walls counterintuitive but indeed improve efficiency. The tyre flexes while in motion no matter how low or how high the profile is and so when flexes it uses energy and when softer uses less energy.
But this is different from when the tyres are on low pressure and increased contact patch. The reason I prise so high Goodyear efficient grip performance is exactly that, great efficiency, superb comfort and excellent handling characteristics, best grip in all conditions. 👍

[Max_Headroom]

41 minutes ago, TonyHSD said:

All mk3 Yaris body roll more than Yaris mk4 and it’s because of three major factors: 

Centre of gravity

tyre tracks

and chassis stiffness 

I don't think anyone is disputing that we were discussing body roll in MK3 it seems the pre facelift were bad for it.

[Cyker]

That is indeed very counter-intuitive, I'd really like to see some articles to explain if you can find it again! I mean, if it's 'springier', then I can understand that, but just being soft I don't get how that would reduce rolling resistance  

Always open to more info! (Or Input! Input! as Johnny 5 would say  )

[Mojo1010]

29 minutes ago, Cyker said:

That is indeed very counter-intuitive, I'd really like to see some articles to explain if you can find it again! I mean, if it's 'springier', then I can understand that, but just being soft I don't get how that would reduce rolling resistance  

Always open to more info! (Or Input! Input! as Johnny 5 would say  )

You are correct soft tyre increase rolling resistance. 

[turtle15]

5 minutes ago, Mojo1010 said:

You are correct soft tyre increase rolling resistance. 

A softer thread (more grip) yes; a softer construction seems not.

[turtle15]

I've been looking at the specifications of the latest alignment and found very strange values: on the rear axle I have 0º22' toe on the right wheel and 0º19' on the left wheel (positive toe). Can anyone who knows alignment confirm that these are ridiculous values? It's supposed to be between 0º02' and 0º16'...

[TonyHSD]

17 minutes ago, turtle15 said:

I've been looking at the specifications of the latest alignment and found very strange values: on the rear axle I have 0º22' toe on the right wheel and 0º19' on the left wheel (positive toe). Can anyone who knows alignment confirm that these are ridiculous values? It's supposed to be between 0º02' and 0º16'...

Hi, 

I don’t t know about the values but I know that rear axle it’s not adjustable but can go off alignment as a result of front axle not properly aligned or not properly centred at the machine before procedure. If you in doubt about it best to double check. Usually bad alignment is felt when driving on straight roads at speeds , heavy winds, the car simply feels like fighting with the road and has no straight line move tendency.  
Here if this can help 

[turtle15]

On 4/6/2023 at 11:36 AM, turtle15 said:

I've been looking at the specifications of the latest alignment and found very strange values: on the rear axle I have 0º22' toe on the right wheel and 0º19' on the left wheel (positive toe). Can anyone who knows alignment confirm that these are ridiculous values? It's supposed to be between 0º02' and 0º16'...

Yesterday I was looking at the wear on the rear tires and they are wearing more on the outside, which is exactly a symptom of excessive toe-in and corroborates the alignment figures. Considering the type of suspension and that the right and left side values are quite similar I think it may have come that way from the factory. Can anyone check if any TSB has been released for this situation?

I also changed the tire pressures and put the normal pressure (not the "eco") which is 33 psi in the front and 32 psi in the rear. The body roll has gotten a lot worse and now the tires squeal in the turns, however, the ride quality has improved and car feels calmer (on the straights, obviously 😂). When I get out of the car and close the door (without too much force) the car sways for about 2/3 seconds, as if it were on balloons. I think that if really the tires, namely the sidewall, were not a decisive factor for the body roll, I should not feel so much difference in lowering 3 psi, do you agree?

[flash22]

i would do a bounce test and see what does, the shocks may physically look OK but, also inspect the springs especially the ends

the 1.0 tend to have younger owners, and they do get used and abused

[turtle15]

30 minutes ago, flash22 said:

i would do a bounce test and see what does, the shocks may physically look OK but, also inspect the springs especially the ends

the 1.0 tend to have younger owners, and they do get used and abused

Do you know anything about excessive toe-in of the rear axle (TSB)? If it came like that from the factory I must not be the only one affected. 

When it comes to the bounce test, I can say that if you press the rear axle down, the car comes back up in a single jump quite quickly. Plus the car has very few miles and underneath it looks like brand new.

[flash22]

TSB ? Not what I'm aware of

spec for the rear toe-in

		175/65 R15        1KR-FE        1NR-FE        1ND-TV                               C + D 0°20' +/- 15' ( 0.33° +/- 0.25°)                                      B - A: 3.7 +/- 3.0 mm (0.145 +/- 0.118 in.)

 

[turtle15]

12 minutes ago, flash22 said:

TSB ? Not what I'm aware of

spec for the rear toe-in

 

I can't see the specification...

[turtle15]

24 minutes ago, flash22 said:

TSB ? Not what I'm aware of

spec for the rear toe-in

175/65 R14	1KR-FE	C + D   0°19' +/- 15' ( 0.32° +/- 0.25°)
		B - A: 3.3 +/- 3.0 mm (0.130 +/- 0.118 in.)

 

Thank you very much. So it seems that my toe-in is completely within specification and that the correct range that appears on the alignment sheet is wrong. Nevertheless, I think it's a fairly aggressive toe-in (to improve straight-line stability?).

I think that the next time I perform an alignment I have to pay some money at Toyota-Tech and take the correct values myself since the ones specified by the alignment machine are wrong 😠.

[flash22]

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