low profiles on stock wheels???????

[cwb11698]

Alright I recently got my first car and it is an awesome one! I got a 94' Infiniti J30T. Well im shoping for ideas that would make my car look better. Im going to the angle eyes and im going to tint my windows. But i wanna do low profile tires I see all kinds of cars with them and most of them look good. So my question is, can i go with low profile tires on my stock set of wheels?:help

[elbles]

Yes, you could go to low-profile tires on any car with any rims really, but by doing so, you would be changing the circumference/diameter/radius of the wheel and tire combination, which in turn throws off your speedometer and odometer. It would probably just be slightly off, but regardless of how you feel about it, it is certainly possible.

[AZhitman]

Better to add width than reduce sidewall height.

What tires are on it now?

[maxnix]

Better to add width than reduce sidewall height.

Best to meet or exceed the OEM required load carrying capacity while maintaing the factory rolling diameter.

[cwb11698]

Right now I have what was on the car when I bought it and they are Riken Raptors p215/60R15.... Im not really to worried about my gaugues being off becasue I can have that fixed. I just dont want to drop a whole bunch of money into low profiles and have them look really bad!

[maxnix]

You will be well served by doing a search on tires (among other topics) and reading the posts. Riken is not even on the radar.

Might reread the post above your last one also.

__________________Brian1995 Q45 & Q45t

Discover the power of the button!

[cwb11698]

What is good tire that you suggest, that will give good performance and good looks?

[AZhitman]

http://www.discounttiredirect....ize=0

Any of these would be an improvement over what you have.

[maxnix]

Please read the posts. Might try searching on the word "tires."

To paraphrase Benjamin Franklin, all tires are black when you are in the car.

__________________Brian1995 Q45 & Q45t

Discover the power of the button!

[cwb11698]

Well after looking around alot I have decided to go with the Dunlop SP A2or the Sport 5000. I am leaning towards the A2 so if anyone has had expierence with either of these tires let me know. Thanks for everyones help.-Chris-

[PalmerWMD]

Chris,

the dunlops are ok but spedny for what they are.Tires with good repuations here are:

Michelin Pilots Firehawk SZ50EPYoko s100

Fred..

[Highway Q45]

There's a good site with tire size calcs. It will give you the speedometer error in 5 mph increments. A real downside to smaller diameter tires is the "extra" odometer miles it will add if you can't correct the speedo gear.

http://www.dakota-truck.net/TIRECALC/tirecalc.html

Steve

[RobHakari]

how hard/expensive is it to have the speedo readjusted?

[Q45tech]

Impossible to have the speedo recalibrated as the speed sensor produces a frequency that varies with drive shaft speed and an IC in the speedometer translates that to a voltage for the meter, the steering computer, the cruise control the ecu and the transmission ecu all use the 0-5 volt range voltage.

What is available are different nylon gears for the speed sensor to allow the same sensor to be used with all Nissan transmission with differeing rear differential gear ratio sets.There are gears for 3.538, 3.694, 3.90, and 4.083 plus 3.31 ...........in between say a 4.5-7% change you are out of luck and have to live with errors.

It is possible to mechanically change the low /top extreme weights on the speedometer to accutaely reset 60 mph but at the expense of errors everywhere else .........but the ecu and all other systems dependent on speed sensor output will still be WRONG!

[BadQ45t]

I don't think you should worry about it, but with those stock rims I do not think you can do much. I'd suggest going to 225/50 15 that is a good size to convert to, I did that on my 84' 300ZX from the same size your car came with. There are some good tires available in that size. Keep in mind you will see more wheel well, I did the 1" Eibach lower springs so that got rid of alot of it, but you will feel a bit more width on the road.

[SmithSR]

Let us examine...

215/60-15 Overall Diameter(OD) is 25.16"225/50-15 OD is 23.86"

Let's see how this affects the "effective axle ratio" of the car....meaning instead of changing the actual gears, we change the size of the tire that the engine's torque must turn. To find effective axle ratio, we first find the tire revs per mile:

20,800 divided by OD=Tire revs per mile

so: 20800/25.16=826.7 and: 20800/23.86=871.1 tire revs per mile

now we find effective ratio using:new tire revs per mile/old tire revs per mile, then multiply by original axle ratio. This will give us your effective axle ratio.(Using 3.73 in generalization, since I don't have J30 specs in hand)871.1/826.7 x 3.73 = 3.93 effective axle ratio.

now on to actual speed vs. indicated speed. Use this formula:old tire revs per mile/new tire revs per mile multiply by indicated speed will give you actual speed: lets say your speedo reads 55mph

826.7/871.1 x 55mph indicated speed = 52.1 mph actual speed

Be sure to at least keep this in mind when considering a change in overall tire diameter. These aren't huge differences, and Q45tech will tell you that there are percentages of errors in measurement, but it's good to know what's going to take place when you deviate from original equipment.

For arguement's sake, the 225/55-15 (OD is 24.74")is available in <some> brands, and will get you closer to OEM readings than 225/50-15. It will also increase width, as Hitman said, while staying close to OEM tire OD.

[Q45tech]

In many respects tire life is a function of the percentange of safety factor used........the government use to require that the manufacturers used no more than 85% now 88% of actual static weight vs maximum sidewall load weight.

The higher the load rating on a tire the stronger it is. The greatest mistake made in tire selection is fitting a weaker tire [load index] in an attermpt to get a wider foot print.

We have seen good sucess with 225/60/15.............if extreme performance is desired go with the Firestone SZ50EP in that size it will transform the J!

[szh]

We have seen good sucess with 225/60/15.............if extreme performance is desired go with the Firestone SZ50EP in that size it will transform the J!

Heartily agreed! I use this size and tire on my Q currently (although I am about to increase to 17" wheels) and it was an awesome difference. I have waxed eloquent about this tire before, so I will not get too carried away here again!

Z

[SmithSR]

Info on Firestone SZ50EP from the BFS website.