[subysti5486]

hey everybody, i gotta get new tires for my car and my wife was suggesting to buy 2 tires have them put on and then in 2-3 weeks buy the other 2(for money reasons). i know with our cars its bad for our diffs, how bad is it and what can happen if i do it this way? i told her its bad but i didnt know exactly how to convince her to buy all 4 together. please help me out

[subysti5486]

any experts on this?

[tyler_sti]

It really depends on how you drive the car. How many miles a week does it see, and how bad are you're current tires? You can't just wait 3 weeks to get all 4? IMO, if you're not driving more than 30miles a day and just normal city driving you should be fine.

[subysti5486]

yea ill probably buy two and wait a couple weeks and buy the other two and put them on, i was just curious cause i just heard it will mess up the diff but no one seems to know exactly what will happen. and i have threads showing on my current tires so i need new ones but i can wait a little bit i guess

[TorstenW]

I was told by some Subaru techs that the circumference of the new vs old tires should not be more than approx 1/4 inch off. That's front to rear only, don't switch side to side unless you want nascar style stagger for left turns only. That way the center diff won't build up too much heat under normal driving. Watch your diff idiot light just in case, and stay away from anything close to redline in top gear, lol...


Seriously though, I had this on my car for several weeks and nothing happened at all.

[T3h_Clap]

the diff idiot light is only for the rear.

are the 4 new tires identical to the 4 old tires?

[upncummr]

Rather than risk any damage to the car, why not just put the four new tires on the car now? Even if that means putting two of the tires on a credit card for two to three weeks, it seems to be a better solution than driving around on mismatched tires especially when the "old" tires have threads showing.

Don't be penny wise and pound foolish.

Gary

[solovus]

I suggest buying them together...you don't want different diameter wheels at all because the car will constantly be working to compensate for the differences in tire rotation (smaller diameter will complete a revolution before the first). This isn't a problem really on RWD or FWD since only two tires are driven, but clearly we don't have the luxury of installing only two new tires...I personally wouldn't do it.

[sleepsindirt]

.dont do it,buy 2 let them sit in the garage/living room. in 2-3 wks buy the other two,and mount all 4 at once.if your old tires are bad,be cool no speeding,or driving like a nut.they should hold,as long as your chill.

[upncummr]

If you need something that will convince your wife, just show her your owner's manual.

Here's an excerpt from the 2005 STi Owner's Manual re: tire replacement.

��

Tire replacement

The wheels and tires are important and integral parts
of your vehicle’s design; they cannot be changed arbitrarily.
The tires fitted as standard equipment are optimally
matched to the characteristics of the vehicle and
were selected to give the best possible combination of
running performance, ride comfort, and service life. It
is essential for every tire to have a size and construction
matching those shown on the tire placard and to
have a speed symbol and load index matching those
shown on the tire placard.
Using tires of a non-specified size detracts from controllability,
ride comfort, braking performance, speedometer
accuracy and odometer accuracy. It also creates
incorrect body-to-tire clearances and inappropriately
changes the vehicle’s ground clearance.
All four tires must be the same in terms of manufacturer,
brand (tread pattern), construction, and size. You
are advised to replace the tires with new ones that are
identical to those fitted as standard equipment.
For safe vehicle operation, SUBARU recommends replacing
all four tires at the same time.

�� All four tires must be the same in terms of
manufacturer, brand (tread pattern), construction,
degree of wear, speed symbol, load index
and size. Mixing tires of different types, sizes or
degrees of wear can result in damage to vehicle’s
power train. Use of different types or sizes
of tires can also dangerously reduce controllability
and braking performance and can lead to
an accident.

�� Use only radial tires. Do not use radial tires
together with belted bias tires and/or bias-ply
tires. Doing so can dangerously reduce controllability,
resulting in an accident.

Hope this helps.

Gary

[sleepsindirt]

thats the ammo^^

[subysti5486]

hey thanks eveybody for your input! ill have another chat with the wife.