tire size change -will it throw codes..???
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i'm gonna try some new tires on my Z..but since i have 19 fronts and 20 rears................
the choices are somewhat limited..especially when you don't want to throw a code...
the stock tires diameters are about 25.4" ft and 26.1" rear..variance of 7/10th ..
currently i have 25.6" ft and 25.9" rear a variance of about 4/10ths of an inch.
no code problems..
here is my question...
i want to go with new size tires with dia. of 26.6" ft and 27.2" rear..a variance of 6/10ths
..basically about an inch taller ft and rear...will it work?
width's are about the same...the big dif is the rear tire..
i have a 305x25x30 and want to go to a 305x30x20????
will it throw the dreaded code for T/C and A/H ???
thanks guys for any input,
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i'm gonna try some new tires on my Z..but since i have 19 fronts and 20 rears................
the choices are somewhat limited..especially when you don't want to throw a code...
the stock tires diameters are about 25.4" ft and 26.1" rear..variance of 7/10th ..
currently i have 25.6" ft and 25.9" rear a variance of about 4/10ths of an inch.
no code problems..
here is my question...
i want to go with new size tires with dia. of 26.6" ft and 27.2" rear..a variance of 6/10ths
..basically about an inch taller ft and rear...will it work?
width's are about the same...the big dif is the rear tire..
i have a 305x25x30 and want to go to a 305x30x20????
will it throw the dreaded code for T/C and A/H ???
thanks guys for any input,
I think you are confused about how to designate the tire sizes you have now and want to put on your Vette.
I just replaced the tires on my Z06. I took off the following:
Front - 275/35R18
Rear - 305/30R19
I installed:
Front - 285/30R19
Rear - 325/25R20
Now, what sizes are you replacing?
What sizes are you installing?
-
i'm not confused , just not clear

on the car now..
275/30/19
305/25/20
i want to install
275/35/19
305/30/20 ..
the stagger is about 6/10"... stock is about 7/10...
bud
stocks are: 25.3 f, 26.1 r
new ones: 26.6 f, 27.2 r
that's a difference of +5.1% f, +4.2% r. that's increasing the front & rear size by almost the same amount, so you should be fine.
make sense?
thanks again guys..

Using the following calculation, I find your present tire diameters to be:
275*.6*0.03937+19 = 25.50 inches for the front
305*.5*0.03937+20 = 26.00 inches for the rear
Your proposed new tires are:
275*.7*0.03937+19 = 26.58 inches in the front
305*.6*0.03937+20 = 27.20 inches in the rear
The stagger is okay and you should not generate any codes.
Questions I have about your selection of tires are:
1) Why so tall?
2) Have you had these tires on your Vette?
3) Do you have clearance in the wheel wells under jounce and in the front at full lock?
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i believe there is room on the rear's..too me the 20's that have been on.. look funny there is so much room,tires look like rubber bands..
.
and i've noticed that i'm about 4-5 mph below shift points to rev limit..course that size makes it "snappy" in the low gears..
i'm gonna look at the fronts carefully...it will be close..but car is at stock height settings..and there seems to be room..
thanks pic of current tires


bud
Last edited by bud miller; May 3, 2011 at 09:23 AM.
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so nitto invo..makes a 315x35x20 for the rear...but its 28.6 " dia..it should fit..i have a lot of room..so im looking at what i have on car now
ft 275x30x19 25.6
r 305x25x20 25.9
going to
275x35x19 26.6
315x35x20 28.6
but what will that do to the stagger..or computer A/H ?
i'm guessing about 2.0" stagger..
any thoughts?? anybody else running about a 2.0" difference front to rear..
thanks again...
i believe there is room on the rear's..too me the 20's that have been on.. look funny there is so much room,tires look like rubber bands..
.
and i've noticed that i'm about 4-5 mph below shift points to rev limit..course that size makes it "snappy" in the low gears..
i'm gonna look at the fronts carefully...it will be close..but car is at stock height settings..and there seems to be room..
thanks pic of current tires


bud
Bud,
You have a very nice looking Vette.
My advice upon seeing it is to lower it from its present station wagon ride height to a ride height closer to what my Z06 is set at.
/

thanks for the ideas...though..
my only other concern will be the speedo...a 1 1/2" increase my throw it off..
Last edited by bud miller; May 4, 2011 at 02:29 PM.












