Mixed tire brands, handling problems
Thread Starter
Le Mans Master
Joined: Oct 2005
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From: Metro Detroit Michigan
Mixed tire brands, handling problems
Thought I'd post this in case it's useful to someone else.
With my original run-craps, street handling was decent and predictable.
When they wore out in the back, I replaced the rears only with Nitto 555s.
These held the power better than the Goodyears, but the car became a bear to drive! Followed every groove and pavement irregularity (Michigan roads aren't too good) and jerked all over the place. Almost changed lanes unintentionally a couple of time.
Fronts finally wore out, replaced them with Nitto 555s, same as the rear.
The car is happy again. So am I.
With my original run-craps, street handling was decent and predictable.
When they wore out in the back, I replaced the rears only with Nitto 555s.
These held the power better than the Goodyears, but the car became a bear to drive! Followed every groove and pavement irregularity (Michigan roads aren't too good) and jerked all over the place. Almost changed lanes unintentionally a couple of time.
Fronts finally wore out, replaced them with Nitto 555s, same as the rear.
The car is happy again. So am I.
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St. Jude Donor '05-'06-'07-'10
Good post, 
it seems that more people need to be aware of this. I want to add to your point a bit. Mixing brands is usually not a good idea but mixing run flats with non-runflats is an even worse idea. The stiff sidewall of the runflats vs. the standard sidewall of non's will surely wreak havoc with your handling making the car diabolical.
Paul
it seems that more people need to be aware of this. I want to add to your point a bit. Mixing brands is usually not a good idea but mixing run flats with non-runflats is an even worse idea. The stiff sidewall of the runflats vs. the standard sidewall of non's will surely wreak havoc with your handling making the car diabolical.Paul
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Thanks for the heads up. This could save a lot of frustration by other Vette owners.
Drifting
Joined: Sep 2003
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From: Prosper TX
Any time you run a mix of run flat with non-run flats that is going to happen.
Run Flats have stiffer sidewalls. You rears were flexing way sooner than the fronts and are able to track quicker because of it (hence darty). For that matter you should have felt it in high G turns as well and had it feel like the rear might kick out sooner than it used too with run flats.
Mixing 250 mile rated run flats and 50 miles ones will cause the same issue but not to the extent of what you saw.
Run Flats have stiffer sidewalls. You rears were flexing way sooner than the fronts and are able to track quicker because of it (hence darty). For that matter you should have felt it in high G turns as well and had it feel like the rear might kick out sooner than it used too with run flats.
Mixing 250 mile rated run flats and 50 miles ones will cause the same issue but not to the extent of what you saw.
Race Director
Joined: Jul 2004
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From: Lake Havasu City, AZ
You can also get the same problems with mixing series tires ie 35 series with 55 series or with mixing speed ratings.
All the issues are related to the difference is sidewall stiffness.
All the issues are related to the difference is sidewall stiffness.
Melting Slicks
Joined: Aug 2004
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From: Springhill FL
I did exactly the same thing with old runflats still on the front and new Kuhmos on the back. Thing would swerve out of nowhere like it was steering with the back wheels. It was tough to stay in my lane on dry roads...and wet roads were just plain scary. Once i got the new kuhmos on the front(with my new rims 
) it rode like a dream 
Here is my post a few months back about it
http://forums.corvetteforum.com/show...um_id=1&arch=1
) it rode like a dream Here is my post a few months back about it
http://forums.corvetteforum.com/show...um_id=1&arch=1
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St. Jude Donor '06 thru '15, '19
I have the origan runcraps on the front ,replaced the rear with Kumo non runflats .I really havent had a problem with handling so it seems, I will be replacing the fronts tommorow so maybe I will find out what I have been missing .
Melting Slicks
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From: PNW Cougar Country WA
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Run Craps on the front were worn out when i bought my 2K but the back ones looked like about 80%. Had probably been replaced since the car had 20K miles on it.
Put as Set of Pirelli Zero Nero A/S on the front(figured i could replace the back later if need be). Improved the ride considerably and no road darting with probably a much softer sidewall (A/S). Have had it up to 120 mph on the straight and corners 40mph curves at 60+mph no problem. Have over 5K miles on this setup.
Only hopping i get is taking a corner fast and hitting a bad pavement change at the same time, and it is minor. It may make a difference what suspension you are running, mine is stock FE1 - Soft Ride.
I do look forward to an even better ride and noise when i change the back but it is working great now with plenty of tread left there.
Only problem i can see is running hard in the rain. Don't think the back run craps would keep up with the Pirelli's on the front. But i try to avoid the rain, and wouldn't run hard with a Vette in the rain any time, no matter what tires i had on it. Just the width of the tires makes them prone to Hydro, or sliding in turns, in a heavy rain IMO.
Put as Set of Pirelli Zero Nero A/S on the front(figured i could replace the back later if need be). Improved the ride considerably and no road darting with probably a much softer sidewall (A/S). Have had it up to 120 mph on the straight and corners 40mph curves at 60+mph no problem. Have over 5K miles on this setup.
Only hopping i get is taking a corner fast and hitting a bad pavement change at the same time, and it is minor. It may make a difference what suspension you are running, mine is stock FE1 - Soft Ride.
I do look forward to an even better ride and noise when i change the back but it is working great now with plenty of tread left there.
Only problem i can see is running hard in the rain. Don't think the back run craps would keep up with the Pirelli's on the front. But i try to avoid the rain, and wouldn't run hard with a Vette in the rain any time, no matter what tires i had on it. Just the width of the tires makes them prone to Hydro, or sliding in turns, in a heavy rain IMO.
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From: HOUSTON
St. Jude Donor '06 thru '15, '19
They must have been replaced on the rear? I only got 11,000 out of the rear runcraps ,I have about 22,000 on the fronts and could probaly go another few thousand. I have a slight shake at about 80 and think I have a tire out of balance and so I ordered the fronts .
Melting Slicks
Joined: Apr 2005
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From: PNW Cougar Country WA
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Originally Posted by mojo1
They must have been replaced on the rear? I only got 11,000 out of the rear runcraps ,I have about 22,000 on the fronts and could probaly go another few thousand. I have a slight shake at about 80 and think I have a tire out of balance and so I ordered the fronts .
Yes, my experience is balancing, alignment, shocks, suspension will cause you more problems than tires that are in good shape. That is if you are driving fairly normal for conditions.
Melting Slicks
Joined: Apr 2005
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From: PNW Cougar Country WA
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Originally Posted by Skull One
Any time you run a mix of run flat with non-run flats that is going to happen.
Run Flats have stiffer sidewalls. You rears were flexing way sooner than the fronts and are able to track quicker because of it (hence darty). For that matter you should have felt it in high G turns as well and had it feel like the rear might kick out sooner than it used too with run flats.
Mixing 250 mile rated run flats and 50 miles ones will cause the same issue but not to the extent of what you saw.
Run Flats have stiffer sidewalls. You rears were flexing way sooner than the fronts and are able to track quicker because of it (hence darty). For that matter you should have felt it in high G turns as well and had it feel like the rear might kick out sooner than it used too with run flats.
Mixing 250 mile rated run flats and 50 miles ones will cause the same issue but not to the extent of what you saw.
Pro
Joined: May 2004
Posts: 669
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From: CA
The culprit is called "slip angle", and mixing brands, or RC's to non RC's, is a bad idea. For instance, if the rears now have a larger slip angle than the front, you will get from serious to dangerous oversteer. Adjusting tire pressure can help some, but the best idea is to buy four tires of the same manufacture. The cost is worth the safety.
Melting Slicks
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From: PNW Cougar Country WA
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Originally Posted by Mike McCoy
The culprit is called "slip angle", and mixing brands, or RC's to non RC's, is a bad idea. For instance, if the rears now have a larger slip angle than the front, you will get from serious to dangerous oversteer. Adjusting tire pressure can help some, but the best idea is to buy four tires of the same manufacture. The cost is worth the safety.
This is always the best, but maybe not always the problem some posts indicate. Some of the sever problems metioned here maybe be related to more than just a different tire set...IMO
