[coldstaindtears]

I was looking at new tires and am on a budget. I know stock for a 2003 v6 Mustang is 225-55-16; what I want to confirm is that a 225-60-16 tire (the ones I'm looking at are like 15-20 dollars a tire cheaper!) will mount on a stock rim and on the car. I know the car will sit slightly higher and the speedometer will be slightly off as well. I don't mind either, especially since I have a Borla Side exhaust system which likes to bottom out frequently, so maybe this will help a little as well. As always, I appreciate your help.

Sean

[coldstaindtears]

And....does anyone have a coupon codes for TireRack ?

[Gearbanger 101]

Why not look into a 245/50/16. I had them on my 16x7 Pony wheels and they fit great. Retained the stock tire height and it gave me another 3/4" of width on my contact patch as well.

[coldstaindtears]

Right now I have 245-50-16's on my car and it ate 3-4mpg- want to get some of those mpg's back and save some money on a smaller tire.

[Gearbanger 101]

Originally Posted by coldstaindtears

Right now I have 245-50-16's on my car and it ate 3-4mpg- want to get some of those mpg's back and save some money on a smaller tire.

Deviating 3/4" of an inch in your tire width alone won't cost you 3-4mpg. Your fuel consumption issues lie elseware. I'd start with the simple stuff like tune up, and running the ECU for codes before just throwing parts at it?

[coldstaindtears]

I've been told that the extra 20mm around on all four tires in friction and additional air pressure, can make a bit of a difference (not specifying what that 'difference' is), especially since the added weight is applied directly to the wheels - not like additional cargo. Also, since the circumference of the wheel is changed, there is an effect on the effective gear ratio of the car – in this case the smaller circumference raises the effective gear ratio, putting me at a higher RPM at the same mph while cruising over the stock tire – this is also where I could have lost some fuel efficiency.

I was getting consistent gas mileage of about 25/26mpg for all the years doing the same exact driving route to and from college every week, and literally from the from the fill-up after putting the new tires on, I've never gotten over 22/23 - of course this is marginal and there are many other factors but I was getting a constant 25/26 and have never seen that ever again since the new tires – so I’m convinced there is some correlation... I'm very interested in seeing if this gets even a little bit reversed!

But either way, I just need someone to confirm if a 260/55/16 will mount to the rim and fit on the car.

[coldstaindtears]

Originally Posted by Gearbanger 101

Deviating 3/4" of an inch in your tire width alone won't cost you 3-4mpg. Your fuel consumption issues lie elseware. I'd start with the simple stuff like tune up, and running the ECU for codes before just throwing parts at it?

I'm also not "throwing parts" at anything. I NEED tires.

[Gearbanger 101]

Originally Posted by coldstaindtears

I've been told that the extra 20mm around on all four tires in friction and additional air pressure, can make a bit of a difference (not specifying what that 'difference' is), especially since the added weight is applied directly to the wheels - not like additional cargo. Also, since the circumference of the wheel is changed, there is an effect on the effective gear ratio of the car – in this case the smaller circumference raises the effective gear ratio, putting me at a higher RPM at the same mph while cruising over the stock tire – this is also where I could have lost some fuel efficiency.

I don't see any flaw in the assessment except for the fact that....

1) the extra 20mm added to the tire is to its width, not its diameter and

2)the 245/50/16 is nearly identical in said over all diameter to the stock 225/55/16's. If you want to be specific, they're actually within 1.5mm of one and other in diameter. Really a moot point.

Originally Posted by coldstaindtears

I was getting consistent gas mileage of about 25/26mpg for all the years doing the same exact driving route to and from college every week, and literally from the from the fill-up after putting the new tires on, I've never gotten over 22/23 - of course this is marginal and there are many other factors but I was getting a constant 25/26 and have never seen that ever again since the new tires – so I’m convinced there is some correlation... I'm very interested in seeing if this gets even a little bit reversed!

The difference in weight between the two tires is going to be ounces at best. That's simply not enough to account for a 3-4mpg mileage drop. And the added 20mm in width wouldn't create much additional rolling resistance either. If it cost you mileage in any way, its not an amount you would notice...I'm certain of it.

Originally Posted by coldstaindtears

But either way, I just need someone to confirm if a 260/55/16 will mount to the rim and fit on the car.

Well, to my knowledge nobody makes a 260/55/16, but if one such size did exist, it would bulge slightly, but it would fit on a 7" wide rim.

But if anything, it’s going to worsen your fuel economy over what you have now, not improve it. Yes, you've increase the diameter (considerably...over 2.5") so highway cruising will drop your RPM. But the taller diameter and considerably increased rotational mass is going to require more horsepower to reach and maintain any particular speed level. The ability to increase horsepower means the need for more air and fuel will increase as well, thus decreasing your fuel economy.

Not to mention at 28.5" tall, it’s going to make your car look like a 4X4!!!

[coldstaindtears]

My bad, I fudged up my last post. I was at work, clearly not working very hard, and was typing to fast. I meant 225/60/15 not 260/55/16, sorry about that one. I seem to confused even myself.

When I was talking about the extra 20mm and its possible effect on fuel economy, I meant the extra width of the tire (between the 225's and 240's) which I thought would add a decent amount of friction between the tire and the road across 4 tires - adding better traction but worse MPG. An across 4 tires an additional 80mm of grip which is somewhere around 3 inches.

I also was under the impression that the tires I have on my car 245-50-16 are a lot more in weight once inflated then the stock tire. I guess I have no real way of knowing but from appearance it just seems like it was such a bigger/wider tire then the stock that it would translate into literally pounds of difference between them.

From my 245-55-16 tires to the 225-60-16 - there is only a 1 inch difference in tire diameter (according to this tire calculator). I have no concept of how much of a difference that would make in terms of effective gearing, in all honesty, if it even would make a difference, I assume it would. Do you know of anyway to calculate something like this? Or am I just once again talking about the negligible?

In terms of going from the stock tire at 225-55-16 to the 225-60-16, would you expect noticeable difference in RPM through effective gearing you think, or is that just too small of a difference?


Thanks and sorry about my confusion on the previous post.

[ChingonStang]

DEAR LORD, JUST BUY SOME DAM TIRES!

[Gearbanger 101]

What rear gear ratio have you got in your car right now?