Alloy Wheels!

[darkirv]

i got my 17's today up from the 14inch stockys and notage a big change.. its really sluggish put nicer too drive around and has lots more traction :) anyone else experiance much the same?

[poita]

:nopics:

[MatsHolden]

I thought this car was being scrapped?

[DirtyHarry]

ofcourse its more sluggish...same enginer power...more traction on the road as a result of wider tires

[Wraith]

Sounds nice :)

What exactly do you mean or describe the "more sluggish" part...

Should only really be that way if you've exceeded the original o/a dia. by a substancial margin (in which case you need to adjust your speedo) and or if these new rims are substancially heavier than the stockies(highly unlikely with most aftermarket rims)...otherwise it shouldn't be more sluggish.

[Wraith]

ofcourse its more sluggish...same enginer power...more traction on the road as a result of wider tires

He may have retained the same width of the 14's...??

Also more width dosn't always result in more traction, in fact it can sometimes result in reduced traction...simple case being same vehicle weight over an increased 'contact patch' area results in less pressure over that larger area and therefore less hold or traction - this is explained in alot more depth in several 'wheel bibles' floating around :)

[DirtyHarry]

hmmm i dont know if he upgraded to 17's his rim width would have been increased...his tyre size incresed too...resulting in more "tread"/"rubber" on the road and multiply that by 4 tyres.
as a result the car has to work harder to break this traction...resulting in...the car feeling more sluggish...and consuming more petrol, even if the weight distribution is less per tyre....but then again it could also depend on the tyre type and how sticky it is.
i have even attached a pic to show you the difference in contact area between 14 inch and 17 inch tyres which are upsized

http://img44.imageshack.us/img44/6852/tyres.th.jpg (http://img44.imageshack.us/i/tyres.jpg/)

i know the same thing happend to my cousin..she has a civic and once she went from 14's to 17's her car became a bit sluggish and petrol consumption went up too

[hazrd]

I thought this car was being scrapped?

+1

:confused:

[USC]

I thought this car was being scrapped?


+1 :confused:

[Jerram]

if he went from 14s to 17s I'd say there's a very good chance that the tyre width increased given

-Stock measurement I'm assuming would be something like 195/80R14
-Typical Mag measurement (for 5x110) - 215/45R17 or 225/40R17

so - decent increase in tyre width, probably a slight change in circumference as well.

I worked out that the speedo difference between my stock 195/65R15 and 215/40R17 was around -2% which I like because it gives me a small buffer against getting nabbed

[darkirv]

yeah off the scrap idea :S.... just gonna work on the astra heaps :)... yeah there wider its a dream too drive in the wet.. put some octane boost in my last tank and it dosnt seem to be so bad :) heres the rims i got http://http://www.bobjane.com.au/wheelset-details/wheelsetID/950/idm/17/ispt/Wheels/isu/42.html

[Shay]

if he went from 14s to 17s I'd say there's a very good chance that the tyre width increased given

-Stock measurement I'm assuming would be something like 195/80R14
-Typical Mag measurement (for 5x110) - 215/45R17 or 225/40R17

so - decent increase in tyre width, probably a slight change in circumference as well.

I worked out that the speedo difference between my stock 195/65R15 and 215/40R17 was around -2% which I like because it gives me a small buffer against getting nabbed

the speedo already has a massive buffer....

i went from 195/65 r15 to 215/50 r17 and according to my GPS speedo is spot on.
thinking of droppin to 205/45 r17 next if i can, way way way to much scrubbing atm.

and as ange said, shouldnt be more sluggish unless they are heavier,

[AH08]

This is a good site that compares and shows the difference in tyre/rim height from 14" to 17" (or any size you choose ie 15 to 19 etc) and speedo reading difference.

http://www.miata.net/garage/tirecalc.html

[Wraith]

hmmm i dont know if he upgraded to 17's his rim width would have been increased...his tyre size incresed too...resulting in more "tread"/"rubber" on the road and multiply that by 4 tyres.
as a result the car has to work harder to break this traction...resulting in...the car feeling more sluggish...and consuming more petrol, even if the weight distribution is less per tyre....but then again it could also depend on the tyre type and how sticky it is.
i have even attached a pic to show you the difference in contact area between 14 inch and 17 inch tyres which are upsized

http://img44.imageshack.us/img44/6852/tyres.th.jpg (http://img44.imageshack.us/i/tyres.jpg/)

i know the same thing happend to my cousin..she has a civic and once she went from 14's to 17's her car became a bit sluggish and petrol consumption went up too

Info there is correct, however as said, if the car is alot more sluggish it will have to do with 1) a sustancial increase in diameter and/or 2) a substancial increase in wheel weight, not the new contact patch area... :) and as said a larger contact patch area 'does not' necessarily result in more grip either, that's a common misconception ! better rubber compound and tread design or slick surface does...I'll have to find the time to put up some wheel bible facts on all of this :)

Both your cousins car and darkirv have been affected by the larger o/a diameter and/or the greater weight of the new wheels, as they require more energy to rotate therefore resulting in slower or more sluggish acceleration and increased fuel burn but it will only be very obvious on large deviations from stock :)

[Wraith]

the speedo already has a massive buffer....

i went from 195/65 r15 to 215/50 r17 and according to my GPS speedo is spot on.
thinking of droppin to 205/45 r17 next if i can, way way way to much scrubbing atm.

and as ange said, shouldnt be more sluggish unless they are heavier,

That'll make a big difference, as I had a similar prob with my Cali - went from 225/35 R18's to 225/40 R18's on the same 18" rims and it scrubbed like crazy, but that small increase in profile on the same tyre width has an 11.25mm dia. increase all the way around...

Just make sure to check that your load rating with the 205/45 R17's is still ok. :)

[AH08]

Darkirv, if your wheels were 195/80R/14 (diameter 667.6mm) and you went to 215/45R17 (625.3) you have decreased height and your speedo will shown 100kph when you are actually doing around 94kph.


195/80R/14 (diameter 667.6mm) to 225/40R17 (611.8mm dia) is still a decrease in size and your speedo will show 100kph when the actual speed will be about 92kph.
So I would have thought your car would be reving harder and be quicker off the mark and will use more fuel.

This all depends if you had 195/80/14's as stock....post up the old size and for the 17".

[JR]

215/45 on 17s r not recommended for the astra (in terms of rolling diameter n speedo calibration)
u need to keep it at 215/40.

i went from my 185/65/14s to 215/40/17s. no probs with the speedo.
recently i went back to the 14s (for unavoidable reasons), and i've noticed immediately the car felt slightly more nimble. i wouldn't say less sluggish.
but turning the wheel felt easier - so performing 'evasive' moves were easier.
i'd say it cause of the lighter weight of the 14" rims, compared to the 17s.
the increased contact (with 17s) between the tyre n road would make more of a resistance.
i can't wait to put my 17s back on. suits my car more than the tiny 14s :yikes:

[darkirv]

i got 215/40's