Good Morning All,
I recently had 2 new front tyres on my 159 2.4 ti ? the tyres that were on the front were 235/35/19 so when I took it to the garage they replaced it with the same size, replaced upper and lower arms on drivers side front and did a 4 wheel alignment.
Since picking up the car I realised the rears are 235/40/19 and now understand that it should be 40 all round. I spoke the garage and they can?t accept the front tyres back now because they have been used for a few days ? and they informed me that I shouldn?t have a problem as long as the 2 front tyres are the same.
However, since having the front tyres replaced I have notice that sometimes when I accelerate while turning the traction light flashes on the dash and power is cut temporarily, it may be coincidence but this has only started happening since I had the work done. Tyre pressures are all even 40psi on the front and 36psi on the rear.
My questions are:
1.) How vital is it for me to have 40?s all round ? is it worth me selling these 35?s while they are only a week old, and putting 40?s on the front to match the back?
2.) Could the fact that ive got the wrong profile on the front be causing my traction issue?
3.) Is there anything that could have been disturbed during the work eg. ABS sensor or similar that could be causing an issue?
4.) Does anyone have any other suggestions?
Thanks in advance
You don't say which tyres you had on before, and which after? swapping Goodyears or Contis for cheap Ling Long remoulds would also give poor traction.....
Further, is it just the light coming on and the traction control cutting in, or with the traction control switched off, do you feel when driving there is an actual reduction in traction from your previous tyres? bear in mind they will need to be run in a little bit before giving their optimal performance...
also see below Re: tyre profile. 235/40/19 and changing to 235/35/19 will impact on rolling circumference and speedo reading...but changing to 245/35/19 may not if they have put on a wider tyre to compensate for the lower profile....
I have the exact same issue. Local tyre supplier who know their Alfas very well recommended a new tyre for the front of my 159, a Zeta tyre with 35 profile. Like yours, my rears are still a 40 profile. They explained that some additional width in the Zetas would afford more kerb protection (which I was almost insulted by, given that I avoid being within anything less than a country mile of any kerb, or kerb-looking solid item!!).
Like yourself, whilst turning and accelerating simultaneously, I experience the same traction issues - so thank you to David above for the explanation as to what is going on!
I think I'll be raising this with my tyre provider when the time comes for some replacements. They assured me that the different profiles would be fine on the car as the two fronts matched and the two rears matched - seems the car doesnt like it and I think David has hit the nail on the head as to why!
Glad to know I'm not the only one, and thank you David for the explanation!
Having a lower profile doesn't necessarily matter so long as the outside rolling circumference is the same/similar.
wider tyre and lower profile would still give a similar/same tyre wall thickness and therefore outside rolling circumference. Further to consider is that if you start a tyre with 8mm tread, you can loose 6mm and still be legal but that's 12mm off your diameter and therefore smaller rolling circumference...so the traction control can't be too fine tuned or it'd mess up as your tyres wear and you replace them out of sync front to back.
you can find outside diameter calculator things in 'tinterweb so use that to compare and if its with 2-3% I think is the guideline figure, then you are ok. (also impacts on your speedo reading having non standard tyre size).
worth also noting that non-standard tyres are a modification and ought to be declared to insurer or it is technically void....