13" to 15" Wheels - Acceleration difference?

10th May 2009, 01:56

I've just purchased some 15" 3 studders. Obv i'll need spacers for the rear if i plan on lowering it 40/ 50mm.

Obv the bigger the wheel, the less acceleration.

Would i notice much acceleration difference fom a 13" to a 15"? (195/45/15)

Thanks

10th May 2009, 02:04

ive always thought about this...

surely it would improve acceloration?

cause the circumference of a 13" will obv be smaller than that of a 15" therefore you will travel further from one turn of the wheel.

correct me if im wrong.

10th May 2009, 02:16

Quote:

Originally Posted by dannyboy2005

I've just purchased some 15" 3 studders. Obv i'll need spacers for the rear if i plan on lowering it 40/ 50mm.

Obv the bigger the wheel, the less acceleration.

Would i notice much acceleration difference fom a 13" to a 15"? (195/45/15)

Thanks

The size of the alloy itself isn't too much of a concern dude, it's the alloy plus the tyre.

This is when going from a VTR wheel with tyre to a VTS wheel the straight line performance is almost exactly the same, despite the VTS rim being 1" bigger because the VTR wheel is taller.

However in terms of grip you can expect the VTS rim to behave better because of the reduced sidewall height

Quote:

Originally Posted by marc_mcquilling

ive always thought about this...

surely it would improve acceloration?

cause the circumference of a 13" will obv be smaller than that of a 15" therefore you will travel further from one turn of the wheel.

correct me if im wrong.

not quite dude, although it'll travel more for a single rotation of the wheel it also and more importantly, increases the amount of resistance that engine must first overcome before it can accelerate the vehicle. so in actual fact an overall bigger wheel will actually slow the car down.
small wheels + small tyres ftw
Ads

10th May 2009, 09:26

Quote:

Originally Posted by adsayer

The size of the alloy itself isn't too much of a concern dude, it's the alloy plus the tyre.

This is when going from a VTR wheel with tyre to a VTS wheel the straight line performance is almost exactly the same, despite the VTS rim being 1" bigger because the VTR wheel is taller.

However in terms of grip you can expect the VTS rim to behave better because of the reduced sidewall height

not quite dude, although it'll travel more for a single rotation of the wheel it also and more importantly, increases the amount of resistance that engine must first overcome before it can accelerate the vehicle. so in actual fact an overall bigger wheel will actually slow the car down.
small wheels + small tyres ftw
Ads

Reducing the sidwall doesn't mean more grip Ads.

10th May 2009, 09:32

acceleration will be reduced slightly, but on the plus side your top speed should be slightly better

10th May 2009, 09:33

Quote:

Originally Posted by Toad

Reducing the sidwall doesn't mean more grip Ads.

ok ok steering response then.

10th May 2009, 09:35

Quote:

Originally Posted by Jacobite1745

acceleration will be reduced slightly, but on the plus side your top speed should be slightly better

can 100% say that the top speed will not increase, theorectically it will but to get that higher speed you need horsepower to match.

ads

10th May 2009, 09:50

Quote:

Originally Posted by adsayer

ok ok steering response then.

Not forgeting that the S rim runs a wider (195) tyre than the R rim (185).

The overall rolling radius of 13" vs 15" when both fitted with the correct tyres should be virtual identical! However the 13" steel will most likly be lighter, so acceleration may be slightly less.

10th May 2009, 10:07

Quote:

Originally Posted by adsayer

ok ok steering response then.

Hmm... Maybe.

10th May 2009, 10:35

moved to the appropriate setion

tbh with differnt size rims if you get the right size tyres he circumfrence will not change so wont effect the cars straight line performance
the extra width compared to a steelie will gove more rolling resistance with he bigger contact patch but idoubt youll notice it lol

10th May 2009, 10:53

Wide wheels wont give a bigger contact patch! ! ! !

10th May 2009, 11:14

So a 13" steelie with say a 185/45/13 (aware it probably doesnt exist) accelerate quicker than 185/45/15?

10th May 2009, 14:55

Yes as it has a smaller overall size!

The basic rule is when you go up an inch, you go down 5 on the profile, also for every extra 10mm gained in width you down 5 in profile as well!
Vts 15" 195 45 15
Vtr 14" 185 55 14
13" would be 175 65 13 or 185 60 13

10th May 2009, 15:41

potentially a 15" wheel will have more weight further out which will effect inertia. Certainly I have noticed a massive difference when changing to larger road alloys but mostly in handling and the way the chassis handles bumps.
I have yet to try different size lightweight rims back to back but choosing the right wheel to start with will be like night and day.

10th May 2009, 16:03

I went from a set of 16" Magnesium wheels to some 14" 106 raptors, The acceleration and handling was an unbelievable difference.

10th May 2009, 16:17

Thanks ads.

Thats what i thought, smaller wheels would be quicker as theres less of a wheel to turn, which means less weight.

And i can't see how bigger wheels can get better top speeds. Surley the max speed of the engine is as far as it will go, no matter what size wheels. Obv a massive 22" wheel or something would probally make the top end a bit more but not much

And yes, wider wheels would have better grip, i agree.

I have no PAS, so should be fun

10th May 2009, 16:53

Quote:

Originally Posted by dannyboy2005

Thanks ads.

Thats what i thought, smaller wheels would be quicker as theres less of a wheel to turn, which means less weight.

And i can't see how bigger wheels can get better top speeds. Surley the max speed of the engine is as far as it will go, no matter what size wheels. Obv a massive 22" wheel or something would probally make the top end a bit more but not much

And yes, wider wheels would have better grip, i agree.

I have no PAS, so should be fun

Consider your wheels as gearing, The smaller the wheel the quicker the engine will top out because there is less distance to cover and you will max out your engines top speed ( If it has enough power ) If you have bigger wheels then obviously at a higher top speed the car will keep pulling to a higher speed because there is more distance to travel on the wheels. ( Again if its a decent powered motor. ) This is my opinion maybe its right or wrong in some peoples cases.

10th May 2009, 17:42

Quote:

Originally Posted by Krys_23

Consider your wheels as gearing, The smaller the wheel the quicker the engine will top out because there is less distance to cover and you will max out your engines top speed ( If it has enough power ) If you have bigger wheels then obviously at a higher top speed the car will keep pulling to a higher speed because there is more distance to travel on the wheels. ( Again if its a decent powered motor. ) This is my opinion maybe its right or wrong in some peoples cases.

Thats how i see it too.

10th May 2009, 17:50

Quote:

Originally Posted by adsayer

Wide wheels wont give a bigger contact patch! ! ! !

wider wheel = wide tyre (unless your on the euro bandwagon)
its a wider contact to the road so i thought bigger contact patch???

10th May 2009, 18:17

Quote:

Originally Posted by dannyboy2005

Thats how i see it too.

But you said you don't understand how bigger wheels make a difference to top end

10th May 2009, 18:51

Quote:

Originally Posted by Krys_23

But you said you don't understand how bigger wheels make a difference to top end

Yer, true. I understand that max speed is max speed, you wont go any faster and i understadn wheels work on a simular basis to gears.

10th May 2009, 19:36

Quote:

Originally Posted by Krys_23

But you said you don't understand how bigger wheels make a difference to top end

in theory but it would'nt happen on a sax

If theres a wider width of the tyre theres more contact so more resistance so less acceleration...

10th May 2009, 19:51

Quote:

Originally Posted by marc_mcquilling

ive always thought about this...

surely it would improve acceloration?

cause the circumference of a 13" will obv be smaller than that of a 15" therefore you will travel further from one turn of the wheel.

correct me if im wrong.

yeh i agree about that mate

10th May 2009, 22:36

Quote:

Originally Posted by Krys_23

Consider your wheels as gearing, The smaller the wheel the quicker the engine will top out because there is less distance to cover and you will max out your engines top speed ( If it has enough power ) If you have bigger wheels then obviously at a higher top speed the car will keep pulling to a higher speed because there is more distance to travel on the wheels. ( Again if its a decent powered motor. ) This is my opinion maybe its right or wrong in some peoples cases.

it's wrong in ALL cases krys, although you're totally right about considering wheels as gearing, Consider them as the final drive, which is technically what they are

If you increase the tyre diameter you effectively decrease the final drive... basically that you're able to go faster topping out in each gear.

so at 7000 rpm on a standard vts you do say 35mph in 1st.
at 7000 rpm on a vts with 20" rimz you do say 45mph in 1st.

yar?

now why doesn't this increase top speed... because that's determined by your engine power.

If you put 3,000,000" rimz on a standard VTS is it going to suddenly be able to do the speed of sound?

Quote:

Originally Posted by dannyboy2005

Thats how i see it too.

well it's wrong.

Quote:

Originally Posted by AlexB

wider wheel = wide tyre (unless your on the euro bandwagon)
its a wider contact to the road so i thought bigger contact patch???

nope... it'll be wider but the longitudinal length will be shorter... so overall no change in contact patch area.

Quote:

Originally Posted by Krys_23

But you said you don't understand how bigger wheels make a difference to top end

that's because they don't

Quote:

Originally Posted by dannyboy2005

Yer, true. I understand that max speed is max speed, you wont go any faster and i understadn wheels work on a simular basis to gears.

this the correct.

Quote:

Originally Posted by baker556

in theory but it would'nt happen on a sax

If theres a wider width of the tyre theres more contact so more resistance so less acceleration...

as before... the contact patch doesn't change, but typically wider wheels (with the profile reducing) are able to run softer compounds which WILL affect the rolling resistance

10th May 2009, 22:42

Forget that
I R T Tard!

Bring me my brakes mr sayer!

10th May 2009, 22:46

Quote:

Originally Posted by AlexR

Forget that
I R T Tard!

eh?

Got them...

10th May 2009, 22:51

You know what i meant Sayer i was on the right lines

10th May 2009, 22:55

you'll have a higher speed per gear for bigger wheels... no doubt about that. but if the engine is the same then you won't get a higher top speed

10th May 2009, 23:32

LOL adz, you always write essays but they are so useful. Thanks! (Given)

So a 1.1, 0-60 time is Aprox 12 Seconds with 13" wheels
What about a 1.1, 0-60 time with 15" wheels? perhaps 13 Seconds?

10th May 2009, 23:41

Quote:

Originally Posted by dannyboy2005

LOL adz, you always write essays but they are so useful. Thanks! (Given)

So a 1.1, 0-60 time is Aprox 12 Seconds with 13" wheels
What about a 1.1, 0-60 time with 15" wheels? perhaps 13 Seconds?

I read what I've written back after I've posted it and I always get the impression I've written a rude and angry post! I promise you I'm happy happy happy and I'm just trying to bosh out a message as fast as possible and try to do it clearly so as many people can understand... sometimes sounds condescending but honestly I'm not trying to be!

Danny, do you know the dimensions of the tyres that are on the 13's dude?
It'll be slightly slower, mainly because of the additional wheel inertia - combination of more weight and more weight concentrated towards the tread of the tyre. But a trade off is that the car will corner much much better.

with my 1.5D I went from 14's steelies to VTR rims to VTS rims and each time the cornering improved massively whereas the decrease in acceleration wasn't all that noticeable... mainly because you can feel a 1.5D actually accelerate but you know what I mean

11th May 2009, 00:13

Quote:

Originally Posted by adsayer

I read what I've written back after I've posted it and I always get the impression I've written a rude and angry post! I promise you I'm happy happy happy and I'm just trying to bosh out a message as fast as possible and try to do it clearly so as many people can understand... sometimes sounds condescending but honestly I'm not trying to be!

Danny, do you know the dimensions of the tyres that are on the 13's dude?
It'll be slightly slower, mainly because of the additional wheel inertia - combination of more weight and more weight concentrated towards the tread of the tyre. But a trade off is that the car will corner much much better.

with my 1.5D I went from 14's steelies to VTR rims to VTS rims and each time the cornering improved massively whereas the decrease in acceleration wasn't all that noticeable... mainly because you can feel a 1.5D actually accelerate but you know what I mean

Nah, your not rude. Your crazy Just like your hair!!!

My current 13's, rich tea biscuit's are 155/70/13 (Very thin i know). I can guess it will be slower but was wondering if i'd notice it at all, its a 2" increase. Like you say, handling will be a vast improvement.

11th May 2009, 00:36

yep it'll be a tad bit slower in acceleration but I doubt you'll notice it to be honest dude!

11th May 2009, 08:17

Good stuff clearing this up for the punters Ads.

Just a little help for the top speed increase theory. It will hold true if the initial tyres are impeding the maximum obtainable speed. Or also, the gearbox ratios, as in my case with an S1 gearbox.

With 195/45/15 tyres, I can hit about ~123mph. With 205/50/15 tyres, i can hit about ~132mph. There you go chaps. That's how bigger tyres can give you more top end.

15th June 2009, 22:16

Does this really make a noticable difference?

15th June 2009, 22:38

depends ultimately on the tyre Sissy.

15th June 2009, 22:54

I've just gone from vtr rims with pirelli p700 rubber to cyclones with 195/45/15 yoko s-drives and the difference is amazing!
As Ads said, acceleration feels no different, but ( I know - better tyres help here ) cornering is sooo much sharper
The downside is the ride is alot harsher on the lower profile, but again this could be the type of tyre as well.

15th June 2009, 23:36

going from 13" steels to 15" alloys, for me, made the accelleration a tad slower, as the wheels weigh more. however, in doing so i can go quicker around the corners as the tyres have more grip and the steering feels more responsive

and they look better

19th June 2009, 13:21

when i first my test i had brand new clio and bought some 18's for it, use to struggle over 100 with them on, previously with the smaller wheels (14's) was a bit better with them on, but i got told that altering the wheel size actually messers about the speedo too, that its thinking your going faster/slower than you are.

19th June 2009, 16:40

Only messes with the speedo if the rolling radius changes. Will always change going to 18" as the car probably has 14" as std?
The rolling radius won't change going from 185/55/14 to 195/45/15 for example

19th June 2009, 16:40

Quote:

Originally Posted by col101

Only messes with the speedo if the rolling radius changes. Will always change going to 18" as the car probably has 14" as std?
The rolling radius won't change going from 185/55/14 to 195/45/15 for example

yea thats right

19th June 2009, 16:59

I went from 13" Minilites to 15" SuperT's and didn't notice any difference in accel at all.

19th June 2009, 17:42

you can work out how much your acceleration changes with bigger wheel size, dunno if someones posted this but you have to halve the rim diameter to get the radius, then multiply this number by the aspect ratio then add the radius again. then you times 2pi to get the rolling circumference. for example

155/55/13 - 6.5+(6.5x0.55) which is 10 inches, so the rolling distance is 63"

now for a 195/45/15 this comes to 11.2, rolling distance is 70"

so going from the 13s to the 15s will increase the gearing by about 10% (if you do 100mph at 5k revs you will now do 110mph). but also the torque force will get smaller by about the same amount in each gear. in real life you wont notice a massive difference unless your going fast because you will just change gear a bit later. oh and as saxo speedos read 7-8% too fast id watch the speed near scameras

20th June 2009, 18:24

Quote:

Originally Posted by claff

. in real life you wont notice a massive difference unless your going fast because you will just change gear a bit later.

No, you just wont notice at all.

23rd June 2009, 08:43

will your speedo be out then?

24th September 2009, 16:52

Since putting 15's on my 1.1i, I have noticed that my speedo is deadly accurate...GPS confirmed (That's a TomTom GO 910 - the expensive one

)