different size rims on back and front Q's

[woggin]

heya all,

just wondering a few things regarding tire/rim size.

car details:

94 jzs147 risto

currently running 245/35/19 Maxxis MA-Z1 all around on a set of 19x8 Koya Octane rims!

Now i have purchased a set of stock jza80 rims (the 16" ones) which are 16x8F and 16x9R
which are running sumitomo p225/50z/r16/91w htr50z tubeless steel belted radial and the 245 htr 45z version on the back. (but i wont be using the rears, unless i am going to the strip)

now i have heard that running a smaller rim/tire on the front is dangerous, is this true?? i can only imagine it being dangerous if the tires are way over-sized (circumference wise)
the ma-z1 measure 2054.6 mm whilst the sumitomo's measure 1982.7 mm which is 3.5% smaller...

you always see bogan commodores/falcons running stockies on the back (for obvious reasons) but is there any problem with running smaller on the front!?!?!

standard factory Aristo rim/tires are 225/55/16 which is 2053.8 mm which has a 0.04% to the ma-z1 (for the speedo to read true)

i personally cant see any problem running the sumitomo's on the front with the maz1 on the back, except for a funky looking aristo Razz

i'd like to avoid answers like 'get the right size tire', because thats not what i am asking! I am asking if running smaller rims with a different profile tire will cause any type of erratic behavior in my vehicle?

the fronts are smaller in overall circumference so the car should hypothetically lean over them more, 91 load rating means they are rated to 615kg each, just for additional info!

i have tried to get as much info about the tires in as i can!!!

thanxs all

[fergo308]

Why do you want to mix and match in the first place? Are the tyres on the 19's worn out?

Running a 225 up front and a 245 on the rear is going to increase understeer,and increase rear grip and traction compared to running the same size all 'round.

running the 225/50/R16's on the front and the 245/35/R19's on the rear will feel odd. the front will feel sloppy and less communicative,and it's likely to understeer more,with slower response to transition.

If it was my car I'd swap to the 16's all 'round. the handling will be more predictable with similar profiles front and rear.


Justin...

[Axerus]

I don't see any problem running smaller on the front, I personally have ran 17x9 with 215s and 18x9.5 with 235 on the rear for the last year.

And currently im running a 18x9 215 and a 18x10 225 and have had no problems what so ever.

[twentyEight]

16" Front and 19" Rear is not only pushing it a little far, but it would look stupid.

Having said that, there's a few new cars coming out with different size wheels front and rear. For example, the new Lotus Evora has 18" front (225/40 ZR18) and 19" rear (255/35 ZR19).

[woggin]

Why do you want to mix and match in the first place? Are the tyres on the 19's worn out?
Justin...

the tires are fine, actually brand new, the problem is i am currently running different brake pads on the front rotors(bendix HD on the inside of the caliper and shitty TRD's on the outside) this is because my new rotors are thicker so the caliper fouled on the spokes of the stupidly low offset rims (dam Japs) and i want to use the stockies on the front until i have worn the pads down enough to chuck the 19's back on,

refer to "grinding down a caliper" thread!

thanxs for the info handling, i dont drive it hard around corners, its hard to turn a boat in a hurry

16" Front and 19" Rear is not only pushing it a little far, but it would look stupid.

Having said that, there's a few new cars coming out with different size wheels front and rear. For example, the new Lotus Evora has 18" front (225/40 ZR18) and 19" rear (255/35 ZR19).

can you elaborate on how its pushing it a little far?? pushing it in terms of aesthetics or physical road holding ability?? i dont care about the aesthetics of it, i just want my brakes on! as said above refer to the grinding down a caliper thread for the full story!

thanxs
wog

[Robbos_Toyotas]

theres nothing wrong with running a different size rim on the rear. i dont know if car design has anything to do with it or not, but my old boys 1995 porsche 911 has a 1" different wheel on the back factory. cant remember if its smaller or larger dia - dont quote me but i think smaller rear....my brothers 1978 porsche 911 had this too...and my old 95 model amg c36 had a diff size tyre combination stock - taller profile on front than rear but still 17" rim...

blake

[zombie]

from NCOP11 Section LS Suspension and steering 3 Feb 2006 [PDF: 867 KB]

TYRE ASPECT RATIO
Because of the different handling characteristics, the aspect ratio of tyres fitted to the front axle
should not vary by more than 10 from the aspect ratio of tyres fitted to the rear axle (e.g. 175 65
R14 front and 205 45 R14 rear, has an aspect ratio difference of 20 and is not recommended,
whereas 175 65 R14 front and 195 60 R14 rear has a difference of 5 and has similar handling
characteristics).

[joey]

What about running some 225 40 18's on the front and 205 60 16 or 17's on the rear, is something like that frownd upon/dangerous?
Reason i ask is im wanting to buy a pair of rims/tyres to use for a drift day and 16's or 17's are easier/cheaper to come by, but will it dramatically effect handling capabilities?

[Robbos_Toyotas]

What about running some 225 40 18's on the front and 205 60 16 or 17's on the rear, is something like that frownd upon/dangerous?
Reason i ask is im wanting to buy a pair of rims/tyres to use for a drift day and 16's or 17's are easier/cheaper to come by, but will it dramatically effect handling capabilities?

is the car irs or solid? what probly makes the most difference as far as safety n handling goes is the total outside diameter.....trying to keep it close to the front would be a good thing

[Admiral coFF33]

lol 16's and 19's

[pato]

this is because my new rotors are thicker so the caliper fouled on the spokes of the stupidly low offset rims (dam Japs)

firstly, dont blame the japs for your gay offset australian rims,
and also its a higher offset u have, which is making the rim sit stupidly far in not a lower offset.

and iam still shocked as why u went and bought a new set of rims, to solve a problem that a 20 dollar 5mm slip on spacer would fix.

[pato]

What about running some 225 40 18's on the front and 205 60 16 or 17's on the rear, is something like that frownd upon/dangerous?
Reason i ask is im wanting to buy a pair of rims/tyres to use for a drift day and 16's or 17's are easier/cheaper to come by, but will it dramatically effect handling capabilities?

why those sizes then ????
get a pair of 17x9.5's and i stretch a set of 235's on them that i buy brand new for $80

allmost perfect setup for the budget drifter.
second hand skinny ass high profile tyres are the worst thing for drifting,

[Z2TT]

Dont want to sound offensive, but come on man you have an Aristo, Do it right and put Good rims/tyres all round.

[woggin]

firstly, dont blame the japs for your gay offset australian rims,
and also its a higher offset u have, which is making the rim sit stupidly far in not a lower offset.

and iam still shocked as why u went and bought a new set of rims, to solve a problem that a 20 dollar 5mm slip on spacer would fix.

Low offset is closer to zero, higher offset if further away thus a +38 is lower than the factory +50....

do you really think i would be stupid enough to go buy a set of rims without looking at my options first???

Firstly, i tried a spacer, there isnt enough grip on the lug nuts (IMO) to be considered safe (only 1 turn) and then even if it did fit ok, the rim would sit out past the guard, trust me, i have been stuck on this issue for some time and have thought of all the possible fixes! all of which end up being expensive (i.e. go buy a new set of 19's and sell these, std wheels(cheapest option) planned to go buy a80 17's)

Dont want to sound offensive, but come on man you have an Aristo, Do it right and put Good rims/tyres all round.

yea i know dude, shame ay, but it wont be for long hopfuli, which means ill be able to stick the 19's back on pretty quick!

thanxs
wog

[Pimpin_1JZ]

What about longer studs? Problem fixed?