Any point in going to a one up size?

[VK56VD]

The two vehicles in question are:

'04 Infiniti G35 with factory size 215/55/17. I'm thinking of maybe upgrading to 225/50/17 in this vehicle.

'99 Nissan Maxima SE with factory size 215/55/16. I'm thinking of upgrading to 225/50/16 in this vehicle.

Any advantages/disadvantages? Will the one size up handle better? Would it cause slower/faster acceleration? Difference in fuel mileage?

Thanks

 

[92saturnsl2]

The idea is either to improve certain characteristics or to enhance appearance. It's doubtful that a transition that small will have any noticeable effect on either acceleration, fuel mileage or speedometer accuracy. Keep in mind that while you're increasing width a small amount, you're lowering the ratio of the height to the width from 55% to 50%, so the overall circumference will be very close to the original size. There are several tire size calculators on the web that will tell you exactly how much.

The increase in size you mention is likely to improve lateral grip, and appearance if you are looking for a lower profile, more aggressive looking tire, though this may impact ride quality a small amount.

 

[alreadygone]

Unless wheels are wide enough to handle increased width, you'll probably notice increased center-of-tread wear.

Bob

 

[drivewaytech]

Perhaps this is an avenue I will explore. Even though I follow routine on rotating tires and monitoring tire pressure (5 pounds over car specs), the shoulders always seem to wear sooner than the center. I have experienced this on my personal cars and the company car which all have the original size tires.

 

[CapriRacer]

The way you've described this, isn't what I call going up in size.

Physically, the diameter of the tire is the about the same, but you have gone wider with a lower aspect ratio - and the load carrying capacity remains the same.

To me "going up in size" mean going from P205/60R16 to P215/60R16 - and there are benefits to doing that, provided the rim is wide enough and there's enough room in the fenderwells.

But in either case, a single change like this doesn't have a lot of effect compared to the difference you can get just by carefully selecting the tire. Put another way, if you change tire sizes, the particular tire you select may overwhelm any affect the tire size can would make.

 

[tom slick]

Both of my vehicles have fairly unique tire sizes. I've gone up a size on each to get a better selection of tires to choose from.

I don't know if that applies to your situation.

 

[VK56VD]

I've looked at G35 forums and many are saying to also look into 235/50/17 in addition to the 225/50/17 as both of these sizes are close to diameter of the stock 215/55/17 size.

Would the 235/50/17 increase performance even more?

 

[Quattro Pete]

Originally Posted By: Spartuss
I've looked at G35 forums and many are saying to also look into 235/50/17 in addition to the 225/50/17 as both of these sizes are close to diameter of the stock 215/55/17 size.

235/50/17 is actually closer to the OEM diameter of 215/55/17, so your speedo/odo will be unaffected:
http://www.miata.net/garage/tirecalc.html


Quote:

Would the 235/50/17 increase performance even more?

Maybe slightly more lateral grip, but as others pointed out, unless you get wider rims to go along with these wider tires, the benefit may be minimal - the tire will just bulge out more instead of being properly stretched.

One the downside, the same tire in this new size will be a few lbs heavier and will have higher rolling resistance - this will in turn negatively affect acceleration, braking, mpg.

Whether the differences are big enough for you to notice - who knows, but I'm guessing not.

Also, wider tires tend to be noisier.

As for steering response, the sidewall height of 215/55 and 235/50 is basically identical, so it should remain the same, assuming you stick with the same tire model and speed/load rating.

 

[rpn453]

The wider tire would probably provide a little better traction on a hard launch and hard cornering and increase fuel consumption a little. Hydroplane resistance will be lower and steering may feel a little heavier. I don't think any of those would be impacted enough to worry about for a daily driver. I'd only do it if the factory tire size looks too narrow for the rim. The Goodyear RS-As my car came with were too narrow for my rims, IMHO, and did not even protect the rim at all (if you set the wheel down on the face, you'd damage the finish). They did provide good steering feel though. The Michelin Pilot Sport A/S that replaced them were 1/2" wider (in the same size) so they actually provide a small amount of curb protection and they look way better. Everything about the Michelins is better except that they have a heavier steering feel to them. That's not necessarily a bad thing, but it was quite noticeable.