Please Help!!! Question on new tires.
 

2011 Base 370z
Varrstoen es 2.2.2 19x9.5 f 19x10.5 r; Slightly lowered on Swift Springs
Front tires: Potenza RE760 235/35
Rear tires wore out, switched only the two rear ones from RE760 275/30 to Potenza S-04 285/35
Less than a mile into first time driving after tire change, all warning lights turned on, speedometer turns off. Had it checked up by Nissan factory. They suspect the larger sizing in the rear throws off the computer system such as ABS. I wanted to get larger tires for the front to balance it out. They claim no size tires for the front would be available to match the rear.
Anyone have suggestions on what to do? Would larger tires in the front fix my problem or do I need to get a different set of tires in the back? Please advise.
Thank you very much!

Say what :confused::confused: That dont sound right at all.. I would take it to another dealershit that knows what the hell they are doing. Keep us posted

That's weird...
Perhaps the tire shop damaged some sensor in the wheel well when changing the tires?

^^^ would only turn the low air pressure light on. Not kill the speedo.

If you do want bigger tires for the fronts I'm pretty sure a 255/40 would give you the same increase over stock in the front that you with the rears. About a 4mm difference between the two. Not a lot of all season options at that size but lots of summer tires available. I'm 90% sure you will rub the front tabs with those tires. I have 245/40 (wanted 255 but not available in the tire I wanted) lowered on H&R and I rub going over big dips at speed. I also have 285/35 in the rears and don't have the problems you describe.

That being said I agree that this seems like a bigger issue than the tires.

When you get too much difference in tire diameters. It throws the ABS and other things off. To correct this. You need a larger diameter tire in the front now. You have too much difference in tire diameters. Did a little reseach on Tire Rack for diameters.

You had;
RE760 275/30-19, 25.6 dia.
RE760 235/35-19, 25.5 dia.
No difference in diameter.

Now have;
S-04 285/35-19, 26.9 dia.
RE760 235/35-19, 25.5 dia.
Over an inch in difference. :icon14:

Need for the front;
S-04 255/35-19, 26.0 dia. 3rd choice.
S-04 265/35-19, 26.3 dia. 2nd choice.
S-04 275/35-19, 26.6 dia. 1st choice based on diameters. This tire will fit the rim just right. But you are lowered. So it might rub.
Just my opinion. ;)

yah, just run the right sizes.

245/40/19 front and 275/35/19 (or 285/35/19)

a 245/40 will give you a diameter of 26.7" - only 4mm difference from your rears at 27.9" and closer than a 275/35. A 275 won't have any stretch and will definitely rub the front tabs on any dips/bumps.

245/40 and 285/35 is what I run and it has minimal rub only on big dips. and I'm a bit lower than you too.

Follow up
 

Thank you everyone for the response. I'm going to try and switch out the front tires and see if that fixes the problem. I'm hearing 275/35 and 245/40. Does anyone have suggestions/experience with this sizing? I appreciate all the help.

Lol that's the OEM sport size.

Who in the hell had those other sizes on there?! The fronts were just plan stupid. Closer to square the better.

Damn how low are you? Whats your camber? More negative will help in more than 1 way.

Dropped on H&R Springs - about 1.3-1.5"s. I don't remember the front camber off hand, a little under -2 and within factory specs up front. Rears were like -2.1. I only rub the little tab sections inside the front wheel well - the part that sticks in toward the tire more than the rest of the liner. I don't hit the fender at all. And this only happens on really large dips when driving at speed.

If the tires really are the problem then the 245/40 will fix it without changing your rears. I'm running 245/40 and 285/35 without issues - other than the slight rubbing described above.

Yeah thats a little low and the camber isn't enough. Also to much in the rear. Just food for thought.

If I remember correctly the factory setting on the rear are -1.8. -2.1 isn't that much more and was within the acceptable range noted by Nissan. Was also the lowest they could go without altering the toe too much.

Yeah its in spec (depends who does the alignment) but I don't know what nissans smoking giving those horrible numbers! The fronts get no camber and the rears way to much. Horrible for handling. If you lower you need camber and toe arms. Really is no way around it if you want the setup proper.