195 tyres vs 145 tyres

[marc69]

My 1.2 SPi (bhp of -45!) runs ona set of 195s. I had a puncture so just put the car on a set of standard steels with 145s. The car seemd faster and more efficient.......I have since put it back on the 195s (including new tyre) and it feels sluggish in comparison.

I realise the wieght of the allssios, friction of the larger contact surface of tyres and loss of aerodynamic with the wheels sticking out will have an effect, but is it really noticable or is it just that the lack of roll etc makes it feel slower....

I didn't think that it should be noticable....views?

[blue_peg_16v]

My 1.2 SPi (bhp of -45!) runs ona set of 195s. I had a puncture so just put the car on a set of standard steels with 145s. The car seemd faster and more efficient.......I have since put it back on the 195s (including new tyre) and it feels sluggish in comparison.

I realise the wieght of the allssios, friction of the larger contact surface of tyres and loss of aerodynamic with the wheels sticking out will have an effect, but is it really noticable or is it just that the lack of roll etc makes it feel slower....

I didn't think that it should be noticable....views?

will be down to the wheels being bigger (increased rolling radius) it lowers the gear ratio in effect so makes acceleration slower

[craig green]

Raises the gear ratio..

Try weighing a wheel/tyre from each combo. I expect the alloy & tyre is much heavier. Also dont underestimate the extra drag of the wider tyre.

What you lose in acceleration performance, you more than gain in cornering speed however! :)

[marc69]

ok, so looks faster but goes slower!

[marc69]

oh yes, the cornering is ace with the allessios, the first few corners with the steelies were hairy, the main reason why I went back to the Allessios.

[marc69]

I am surprised though that it does actually make a noticable effect on the acceleration, anyone else had this?

[craig green]

It is more apparent with wimpy engines. Though trying the 145's on an XE engined car would be scary in itself, so just isnt an option.

Best wheel tyre size IMO with less than 100bhp is a 185 on a 14" rim. Really good fun in term sof handling.

[blue_peg_16v]

just fit a bigger engine to gain the performance back lol

[Bubba]

Don't fit 17s (215s)...my 1.3 had them...cornered EPICLY...drove...slow as you like

i did find my standard steelies worked pretty well

[marc69]

It is more apparent with wimpy engines. Though trying the 145's on an XE engined car would be scary in itself, so just isnt an option.

Best wheel tyre size IMO with less than 100bhp is a 185 on a 14" rim. Really good fun in term sof handling.

I have 185s on 14" three spokes, may give them a try with 5mm spacers (are spacers safe?)

Wimpy engine!!!!! Wimpy is way to generous, still can't get over the fact that the 1.2i is nearly 20% lower in bhp than the older carb versions. That's modern progression for you.

[marc69]

just fit a bigger engine to gain the performance back lol

its a mk2 so rusty in all the areas you cant see (i.e. every where structural is shot!)
So won't be investing in a bigger engine, it will probably break the chasiss legs!lol

[draper]

try running 165's on a big heavy vectra, understeer fury in wet islands when running late

[marc69]

try running 165's on a big heavy vectra, understeer fury in wet islands when running late

makes 145s on a nova seem good. 165s standard on a vectra then? If so, that is scarey!

Mind you my Austin Seven (Mini) uses crossplies for shows, now that is seriously scarey for understeer, or nosteer as officially known.

[draper]

nah, there just temp wheels untill i refurb (and can afford 2 new tyres) my alloys

[Rich]

thats what happens with big wheels and an engine that couldnt pull your foreskin back unfortunatly lol

[kiwinova]

thats why i always run 135s on the rear when doing 1/4 miles:thumb: