EraZorX
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You can see from the photos below that while my front tires are fully touching the ground, it seems like the rear tires are not:
The dusty but mostly flat road basically has the same effect of "chalking" my tires to check tire contact.
I am running 275 35R18 tires (Ps4s), on 18x9.5+45 wheels (TC105X by WedsSport), at 32 PSI front and 30 PSI rear.
Stock tires have a tire load index of 90, the new tires have a tire load index of 99.
Alignment is shown below:
So, my question is:
This set up is intended for street use; I'll figure something else out for track tire pressures.
Car is stock besides the wheels / tire changes. The car is on stock suspension with no lowering springs.
I'm hoping someone on these forums can help me, I tried contacting Michelin, but had a strange interaction with them - they first recommended 25psi all around, then changed stance and recommended door jamb pressure (35/33) when I asked them for their reasoning.
The dusty but mostly flat road basically has the same effect of "chalking" my tires to check tire contact.
I am running 275 35R18 tires (Ps4s), on 18x9.5+45 wheels (TC105X by WedsSport), at 32 PSI front and 30 PSI rear.
Stock tires have a tire load index of 90, the new tires have a tire load index of 99.
Alignment is shown below:
So, my question is:
- Is it considered normal for the rear tires to not site fully on the ground, while the front ones do?
- If not, what is the problem?
- Is it related to alignment?
- Despite the differences in camber for the left and right side of the car, the wear looks quite similar on each side - the difference is between the front and rear.
- Is it related to tire pressure?
- When tires are overinflated, there is more wear in the middle of the tire - is that what's happening here for the rear tires at 30psi?
- Looking at the tire load index table (attached to this post), and following instructions for applying tire load index tables, it seems that if my old tire pressures(psi) were 35/33 for stock wheels at a tire load index of 90, the new pressure for load index of 99 "should" be... 25/26 PSI, which seems crazy low. I've set the pressure to be 32/30 as a compromise for a somewhat lower tire pressure that still seems "sane".
- It is very common advice when up-sizing wheels is to increase tire pressure, so it seems like it would make sense for tire pressures to decrease tire pressures. The question is if I decreased it enough.
- Is it related to offset?
- Based on this tool, the scrub radius did change a bit with the new wheel size, but I'm unsure of the real-world impact.
- Is it related to alignment?
This set up is intended for street use; I'll figure something else out for track tire pressures.
Car is stock besides the wheels / tire changes. The car is on stock suspension with no lowering springs.
I'm hoping someone on these forums can help me, I tried contacting Michelin, but had a strange interaction with them - they first recommended 25psi all around, then changed stance and recommended door jamb pressure (35/33) when I asked them for their reasoning.
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