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Anyone tried 275/35R19 rear tyres? - Ride/Handling/Suspension/Brakes/Wheels/Tyres - The Lotus Forums Jump to content
G. Bell

Anyone tried 275/35R19 rear tyres?

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I don't like the slightly stretched look of the stock sized tyre on the rear rim was thinking about going for 275/35R19 rear tyres instead. Given that 275/30R19 is an tyre size option it seems like it shouldn't be out of the question but does anyone have experience of doing this, if so any comments?

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Upgrade today to remove Google ads and support TLF.

I'd be amazed if anyone could tell the difference, honestly.  Go for it.

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No reason why it wouldnt work. 9.5" wheel width is the same as the 20" rears on the S and the 400.

275/35/19 will increase your gearing by about 2% over what you run today, but that makes it almost identical to the gearing on a car running 275/30/20 rears.

Edited by mik

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I need to get tyres all four corners in next 3-5 months I predict 

I am ignorant of tech things so I am unaware of the effects you saying in the thread 

to the simpleton like me if on my NA and I will purchase Michelins as recommended

what size best to go for ? I am only road going no track but I guess I am interested more in looks of the on road .  

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Short answer : I'd go for the 275/35/19

 

Longer answer.

I am not a tyre engineer (although we do have a tyre specialist on this forum). Everything from this point on is a bit theoretical as radial tyres deform at the contact patch - by design - to make said contact patch bigger. The amount of squidge will vary according to tyre type/manufacturer (due to construction, rubber compound, and resultant sidewall stiffness), so the theory will not be perfect, but it wont be a million miles off either.

The bigger the diameter of your wheel & tyre combination, the bigger the rolling radius, and therefore the further the car will go for every rotation of the wheel. 

If we set your oem 255/35/19 as the baseline, a 275/30/19 is 2% smaller, and a 275/35/19 is 2% larger in rolling radius.

Who cares?

(It wont be but) lets assume your speedo today reads perfectly. When it says you are doing 70mph, you are doing a true 70mph.

If you put on a 275/30/19 then you'd be doing a true 68.6mph when your speedo said 70mph.

If you put on a 275/35/19 then you'd be doing a true 71.5mph when your speedo said 70mph.

Neither is a significant enough change to be a concern, and your speedo will be over-reading slightly today (an indicated 70mph is probably a true 67mph or thereabouts)  - so fitting a 275/35/19 probably just brings your true speed closer to the indicated speed. Easy to check with phone/satnav GPS speed readout.

If you replaced your oem wheels with the larger diameter S wheels instead, then the oem 275/30/20 fitted to them is 1.8% larger diameter than your current rear wheel. Which is another reason for my answer above.

Note: there are other factors to consider of course when changing tyre sizes. A slightly wider rear will slightly alter the handling balance that Lotus intended. And the rolling radius of the wheel obviously affects your overall gearing, so a 2% larger rolling radius has the effects mentioned above due to the fact it is increasing your overall gearing marginally. Hence acceleration will be around 2% reduced from where it is today. You wont notice that (you'd see the same kind of change going from a fully worn tyre to a brand new one) but i mention it for completeness. You might also consider mentioning any change to your insurance co. (Not cos it is going to have a negative effect, but cos it is in their interest to avoid paying out any more than theh have to if you ever have an accident, and you dont want that to be a cause of any discussion).

Edited by mik
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I like the short answer lol 

but I bow down to your thorough explanation so I will go with the 275/35/19 in PS4s would I have to go for same in the front but obviously in 18”s?  

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On 14/06/2019 at 13:00, G. Bell said:

I don't like the slightly stretched look of the stock sized tyre on the rear rim was thinking about going for 275/35R19 rear tyres instead. Given that 275/30R19 is an tyre size option it seems like it shouldn't be out of the question but does anyone have experience of doing this, if so any comments?

Stretched look? so why not 285/30?


Darryl & Sue

Proud to drive and own a true British supercar the Evora GT430

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4 hours ago, DarrylV8 said:

Stretched look? so why not 285/30?

For me unless I see them in the flesh I find it hard to visualise but I am also concerned wider you go does the car go further away from the handling spec it was originally designed around ?

but I could be wrong ?

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Fair question, but there seems to be slightly less availability in 285/30/19. I can find Mich Supersports for example, but no PS4 or PS4S?

CDM - if changing all 4 you might want to consider a 235/40 on the front too in pace of the 225? (Cars running the larger wheels have 235 fronts and 275 rears. 400s have 235 fronts, 285 rears.

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6 hours ago, DarrylV8 said:

Stretched look? so why not 285/30?

275/35 is the widest of the two ETRTO 'ideal' options for 9.5" rims, 285/35 is an ETRTO recommended spec but is a little ballooned on the rim. Normally I wouldn't worry but the ballooning and the fact you have an extra 10mm of sidewall will both tend to make the rear of the car wander a lot more. I experienced this with going from 225/35R18 to 275R35/18 on my Z4 on 9" rims. It gave the feeling of the car wanting to wag it's tail (as @JayEmmwill attest to) making you feel you're near the limit of grip but you start to push harder it settles down. Not a problem in a car that's a baby GT wanting to munch miles on fast open B-Roads & A-roads, on the Evora I think it's going to spoil the feel and confidence in the car.

@mikI'd be worried about ballooning the front tyres and increasing the front tyre wall height. This will tend to dampen your turn in a little, as you reduce the sidewall height ballooning a little bit is okay as you're mostly end up with about the same amount of lateral deflection at turn in. For instance going from 225/40 -> 245/35 on a 8" rim actually increased the sharpness of the turn in (and exposed even more deficiencies in the Z4's chassis)

Edited by G. Bell
response to mik's post

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So eventually got this done and I'm now running 225/40R18 Pilot Sport 4 up front and 275/35R19 Pilot Sport 4S on the rear. I really like the look of the front tyre with a slight angle to the side-wall and rear tyres being almost but not quite straight:

20190908_144144_720p.thumb.jpg.ea617e887ba5a68d67a514e3853d15a4.jpg

The only issue is in the dry you can provoke a lot of front push by accelerating around corners. However, in the wet it's much more balanced, when there's negligible grip differences between the PS4 and the PS4S. So I suspect the push is due to the extra grip the PS4S provides rather than the extra 20mm of tread.

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When you say ‘front push’, do you mean understeer?

It’s probably a bit late for you now but the recommended combination for the 18/19” wheels is Pilot Supersports up front and PS4S on the rears. That is a much closer combination of grip levels. 

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Yeah, Understeer but more related to throttle input than speed.

I ordered MPS4 tyres all round but got MPS4 on the front and MPS4S on the rear.

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3 hours ago, Bravo73 said:

It’s probably a bit late for you now but the recommended combination for the 18/19” wheels is Pilot Supersports up front and PS4S on the rears. That is a much closer combination of grip levels. 

Really? 😐

recommended by Michelin or Lotus? I have never seen a mix of tyre versions being suggested before (general comment - not Evora or Lotus specific) ?

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Recommended by our resident tyre expert, @rallyesax.

FYI, the PS4 isn’t available in the UK in 19” and the PS4S isn’t available in 18”. Hence the PSS/PS4S recommendation. 

(This isn’t an issue for 19”/20” because PS4S are available in both sizes). 

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Oh, that must have changed relatively recently then.

Either way, the PSS/PS4S combo is a better performing option than a set of PS4.

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Yes it seems that PS4 is now available in this size. That is pretty recent.

Could be a decent combo for the most "Touring/Road Oriented users"

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That sums my type of driving and on-road driving style.

If I was to regularly track the car I'd be looking at a second set of wheels with something really sticky on like MPSC2, Toyo R888, etc.

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On 08/09/2019 at 22:42, Bravo73 said:

Recommended by our resident tyre expert, @rallyesax

Fair enough - cant argue with that 😎

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Hi everyone I’m new to the forum having bought my car three months ago, been lurking here but this is my first post.

I’ve got quite bad tramlining with my car and it feels quite nervous, the car has done 17k and is almost four years old.

Obviously I’m going to have a four wheel alignment carried out first, but if that doesn’t sort it then I’m thinking of changing the tyres.

Tyres are P zeros with 3mm on the front and 5mm on the back, my previous car had MPSS fitted and they were superb.

So I’m wondering do I just get some Pirelli’s for the front,  but as I only do about 6k a year it’ll be a while before the rears need replacing, though I could sell them I suppose to cover some of the additional cost of the Michelin’s if it comes to that.

It’s really spoiling my enjoyment of the car and I’ve never known any of my previous cars to be affected as bad as this.

Are the Pirelli’s really that bad with still 3mm left on them ?

Cheers everyone I’m awaiting some answers from some of the resident experts on here.

Thanks,

Phill

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Hi and welcome.

It's going to be a combination of things unfortunately.

More than likely the geo. once this is done then you have the problem of tyres that have worn to the old tracking setting. They will still feel 'wrong'. On top of that the I found the p zero's to go 'off' and a bit hard as they wore down.

Get the geo done first by someone who knows the Evora.

After that decide on tyres, but I'd be looking at the ps4s. Do the fronts first if that is where you think the tramlining is coming from, then the rears. If you can run to it replace all 4 at the same time.

 

 

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I got quite bad tram lining with my, 6 year old P Zeros which has been virtually eliminated by the PS4 setup. Point of interest I got about 8k out of my rear tyres going from 7.5mm to 2mm of tread. Also I'd consider 3mm tread minimum death before replacing.

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