i can get 165/80-13 tires for 19 bucks a piece from discount tire's site. it's an optional size but it says plus ZERO. the regular size for my car is 175/70-13.

i want to use them for winter, the 165/80-13 would be narrower which = better, correct? any rubbing issues or anything?

 

I wouldn't. 165/80-13 is 3.3 percent larger in diameter than the 175/70-13. That's a pretty big difference. They might or might not rub; you would have to try them to be sure. They will definitely throw off your speedometer and odometer by that percentage.

What's odd is, I went into the Discount Tire website and it shows no winter tires in 165/80-13, but three winter tires in 175/70-13.

FWIW, the Tire Rack website also shows no tires in 165/80-13, but three in 175/70-13, none of which are any of the ones on the Discount Tire website.

It's also odd that they call that fitment a "plus zero". A "plus" fitment usually refers to a tire that is wider than stock, so this would technically be a "minus zero" fitment...

 

No, actually a "plus" fitment refers to wheel diameter. Going to a 15" wheel, for example, would be a "plus two" fitment. Since the wheel diameter is not changing, it is "plus zero".

The width difference of a 175/70 compared to a 165/80 is not enough to worry about. Just stay with the 175/70 and the various tire options it provides you with.

Mike

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by squareback &raquo;</TD></TR><TR><TD CLASS="quote">No, actually a "plus" fitment refers to wheel diameter. Going to a 15" wheel, for example, would be a "plus two" fitment. Since the wheel diameter is not changing, it is "plus zero".</TD></TR></TABLE>

Nope. "Plus" fitments normally involve wider tread on larger diameter wheels, and "minus" fitments normally involve narrower tread on smaller diameter wheels. For example, the GS-R comes stock with 195/55-15 tires. Put on 205/45-16 tires, and that's "plus one". Put on 185/65-14 tires, as is commonly done with winter tires, and that's "minus one". Narrower tires on the same diameter wheels (which is commonly done for winter tires) are referred to as "minus zero" fitments to note the narrower treadwidth, such as in the second page here, on Yokohama's website.

Of course, from a mathematical standpoint, zero - the change in wheel diameter - is neither plus nor minus.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by squareback &raquo;</TD></TR><TR><TD CLASS="quote">The width difference of a 175/70 compared to a 165/80 is not enough to worry about. Just stay with the 175/70 and the various tire options it provides you with.</TD></TR></TABLE>

 

Plus sizing refers to wheel diameter only; the fact that most larger diameter wheels are wider means that they typically need a wider tire. Let's use a theoretical example. Let's say you have three wheels that are all 7" wide. The diameters of the wheels are 15", 16", and 17". The tire you could put on them all is 205 in width (205/50R15, 205/45R16, and 205/40R17). In this scenario, you have changed the wheel diameter but not the tire width. If the 15" is the baseline wheel, then the 16" is a plus one and the 17" is a plus two. The tire width didn't change a bit. If the larger diameter wheels would have been wider, there may have been a need for a wider tire; regardless of tire width, these are still plus sizes BASED ONLY ON WHEEL DIAMETER.

I'm not trying to be an ***; I just want to make sure correct information is out there. Those of us in the tire biz need to keep everything clear.

Mike

 

My terminology was 100 percent accurate and reflects current usage "in the tire biz". You are correct when you note that the terms "plus" and "minus" refer, respectively, to larger and smaller diameter wheels, when the wheel diameter is different from stock. However, when the wheel diameter is unchanged, and a narrower tire is used, that is indeed commonly called a "Minus Zero" fitment. The Yokohama Tire website (in the link above) is a perfect example of the use of this term. And it was even written by "those in the tire biz".

I'm not trying to be an ***; I just want to make sure correct information is out there.