Why is our tire pressure so high?

bigrob126 · 05-18-2012, 10:57 PM

I was just wondering why the tire pressure that nissan recommends for the 370 is so high? I had a C5 Vett, and have looked at the C6 as well, and the tires were....are of about the same size and profile, and the car weighs about the same as well, and the recommended pressure is 30 all around......although Vetts come with runflats, but I changed mine to non runflats and the 30lbs felt fine! I mean, the pressure should be decided by the size tire and wheel, and the weight of the vehicle, front and rear. If vehicles are basically the same weight and have the same size tires and wheels, the pressure should be about the same or very close, no?
I put 35 in my new tires and it feels way to much pressure for me. Was using 34 in the OEM's. Going down to 33 to check it out.

CSA0890 · 05-18-2012, 11:21 PM

What does Nissan recommend?

bigrob126 · 05-18-2012, 11:56 PM

Quote:

Originally Posted by CSA0890

What does Nissan recommend?

35 at all 4 corners.

Waiz · 05-19-2012, 01:33 AM

35 (cold) is completely normal

TreeSemdyZee · 05-19-2012, 07:29 AM

30 sounds pretty soft for a low-profile tire. That's closer to squishy passenger tire pressure.

Baer383 · 05-19-2012, 08:00 AM

Quote:

Originally Posted by TreeSemdyZee

30 sounds pretty soft for a low-profile tire. That's closer to squishy passenger tire pressure.

34-35 psi cold is right you should try this on 20's

bigrob126 · 05-19-2012, 09:58 AM

I realize 35 sounds about right, probably because that is what nissan says it should be, I was just wondering if anyone knew why or how nissan chose this number, when most other high performance cars with similiar size tires have mush lower recommended pressures. The Dodge Viper's is another, with pressure at 29! I have owned much higher performance cars that this Z and the pressures have never been this high. Besides the fact that I think my car feels like sh-t with this much pressure, and thats why I am going to experiment!

2011 Nismo#91 · 05-19-2012, 09:51 AM

30-35 is the typical range I have seen on all cars. A little higher PSI tends to give you a little better MPG then lower.

Think of it like this higher psi less of the tire needs to contact the road so less friction less lost energy. Lower psi more tire contacts the road more friction. But remember never take your PSI too high or too low it has side effects.

Cmike2780 · 05-19-2012, 09:59 AM

It's all in your head

cossie1600 · 05-19-2012, 09:59 AM

Different tires

CBRich · 05-19-2012, 12:39 PM

A lower tire pressure gives a more comfortable, softer ride. The sort of thing you would expect in a car with an average buyers age of around 55.

wilsonp · 05-21-2012, 12:25 AM

The NSX recommendation was 33F / 40R, so the 370Z isn't really high. I notice a softness in handling when my tire pressures drop to around 32.

Mike · 05-21-2012, 03:42 AM

my wife's Z4 is 36/42. It also depends on the suspension and probably a lot of other factors too.

axeman71 · 05-21-2012, 04:04 PM

The non-sport 18" have an even higher recommendation of 38psi.

05-18-2012, 10:57 PM	#1 (permalink)
bigrob126 Base Member Join Date: Jan 2011 Location: Las Vegas NV Posts: 134 Drives: 2009 370Z Sport Auto Rep Power: 15	Why is our tire pressure so high? I was just wondering why the tire pressure that nissan recommends for the 370 is so high? I had a C5 Vett, and have looked at the C6 as well, and the tires were....are of about the same size and profile, and the car weighs about the same as well, and the recommended pressure is 30 all around......although Vetts come with runflats, but I changed mine to non runflats and the 30lbs felt fine! I mean, the pressure should be decided by the size tire and wheel, and the weight of the vehicle, front and rear. If vehicles are basically the same weight and have the same size tires and wheels, the pressure should be about the same or very close, no? I put 35 in my new tires and it feels way to much pressure for me. Was using 34 in the OEM's. Going down to 33 to check it out. __________________ Rob Last edited by bigrob126; 05-18-2012 at 11:56 PM.

05-19-2012, 09:58 AM	#7 (permalink)
bigrob126 Base Member Join Date: Jan 2011 Location: Las Vegas NV Posts: 134 Drives: 2009 370Z Sport Auto Rep Power: 15	I realize 35 sounds about right, probably because that is what nissan says it should be, I was just wondering if anyone knew why or how nissan chose this number, when most other high performance cars with similiar size tires have mush lower recommended pressures. The Dodge Viper's is another, with pressure at 29! I have owned much higher performance cars that this Z and the pressures have never been this high. Besides the fact that I think my car feels like sh-t with this much pressure, and thats why I am going to experiment! __________________ Rob

05-19-2012, 09:59 AM	#9 (permalink)
Cmike2780 A True Z Fanatic Join Date: Jun 2010 Location: Long Island Posts: 5,059 Drives: slowwww Rep Power: 29	It's all in your head __________________ [09][MB][6-Spd MT][Touring][Stillen Gen III][K&N][Borla CBE][Evo-R] [ArchitTEK Photography]

05-21-2012, 12:25 AM	#12 (permalink)
wilsonp A True Z Fanatic Join Date: Jul 2010 Location: Virginia Posts: 1,134 Drives: 2009 Touring Sp Nav Rep Power: 17	The NSX recommendation was 33F / 40R, so the 370Z isn't really high. I notice a softness in handling when my tire pressures drop to around 32. __________________ 2014 Cayman S PDK Sport Chrono White/Black Was 2009 370Z Touring Sport+Nav 7AT Metallic Black/Persimmon Was 1991 NSX Auto Black/Black

05-21-2012, 03:42 AM	#13 (permalink)
Mike The370Z.com Sponsor Join Date: Jun 2009 Location: Loganville, GA Posts: 5,944 Drives: 370z Rep Power: 2186	my wife's Z4 is 36/42. It also depends on the suspension and probably a lot of other factors too. __________________ NISSAN: 75 280Z / 86 300ZX GLL /87 Sentra SE / 03 350Z / 23 Z Porsche: 93 968 / 23 Macan GTS / 93 968

05-18-2012, 11:21 PM	#2 (permalink)
CSA0890 Base Member Join Date: Nov 2011 Location: Oklahoma Posts: 174 Drives: 2011 Tour/Spt 7AT Rep Power: 14	What does Nissan recommend?

05-19-2012, 01:33 AM	#4 (permalink)
Waiz A True Z Fanatic Join Date: Apr 2010 Location: SoCal Posts: 9,262 Drives: Z33 & GE8 Rep Power: 460	35 (cold) is completely normal

05-19-2012, 07:29 AM	#5 (permalink)
TreeSemdyZee Premium Member Join Date: Dec 2009 Location: Kentuck-IANA Age: 60 Posts: 4,886 Drives: '09 370 & ‘14 Juke Rep Power: 27409	30 sounds pretty soft for a low-profile tire. That's closer to squishy passenger tire pressure.

05-19-2012, 09:51 AM	#8 (permalink)
2011 Nismo#91 A True Z Fanatic Join Date: Mar 2011 Location: NJ Posts: 2,408 Drives: slowly Rep Power: 40570	30-35 is the typical range I have seen on all cars. A little higher PSI tends to give you a little better MPG then lower. Think of it like this higher psi less of the tire needs to contact the road so less friction less lost energy. Lower psi more tire contacts the road more friction. But remember never take your PSI too high or too low it has side effects.

05-19-2012, 09:59 AM	#10 (permalink)
cossie1600 A True Z Fanatic Join Date: Jun 2009 Location: californee way Posts: 5,380 Drives: 370, Leaf Rep Power: 30	Different tires

05-19-2012, 12:39 PM	#11 (permalink)
CBRich A True Z Fanatic Join Date: Apr 2009 Location: SC Posts: 2,464 Drives: 370Z Rep Power: 544	A lower tire pressure gives a more comfortable, softer ride. The sort of thing you would expect in a car with an average buyers age of around 55.

05-21-2012, 04:04 PM	#14 (permalink)
axeman71 Base Member Join Date: May 2010 Location: Augusta, GA Posts: 129 Drives: '10 Conv A7 Blk Chry Rep Power: 15	The non-sport 18" have an even higher recommendation of 38psi. __________________ 2010 Roadster, 7AT, Black Cherry, Touring, Navigation, Lighted Kick Plates, Floor and Trunk Mats.

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