Help a Tire Newbie Please!!!

[Machine]

OK...I don't know anything really about tires....I read a bunch of threads and was totally lost. I have a hopefully simple question. I have a 2000 Ranger Stepside (Flairside) 4x4. Right now I am running 245/75/r16. I am in need of 4 tires bad and yesterday had a blow out. Someone I know offered me a set (with rims) of 265/70/r15 that came off a 1997 Ranger 4x4. Can anyone tell me...will these fit. Will I have any problems? Rub? Handling? Bad gas mileage? Anything? Thanks.

 

[Downey]

they will fit fine they are a little taller shouldn't hurt your gas mileage

 

[Chris.S.]

You list your tires as a 16" rim, but the replacements are 15". Do you have rims for the new ones too?

Old ones diameter is 30.5
New ones diameter is 29.6

So as long as you have rims to fit the other tires you've got room vertically but you may get a little rub on tight turning...


Tire size converter:
http://www.onlineconversion.com/tire_size_conversion.htm

 

[Downey]

^^^ can you read it says they come with rims

 

[Machine]

Thanks all. Is there any difference between the 70 and 75? I mean I know there is a difference, but will it be an issue? What is this difference?

 

[Downey]

a little not much 75 is taller

 

[Machine]

Man that was fast! Thanks for the info. I appreciate. For the price, I guess I can't go wrong. I wish I was going bigger though.....lol. Oh well. Beggars can't be choosers!

 

[sccaSVT]

Right now I am running 245/75/r16. I am in need of 4 tires bad and yesterday had a blow out. Someone I know offered me a set (with rims) of 265/70/r15 that came off a 1997 Ranger 4x4. Can anyone tell me...will these fit. Will I have any problems? Rub? Handling? Bad gas mileage? Anything? Thanks.

Thanks all. Is there any difference between the 70 and 75? I mean I know there is a difference, but will it be an issue? What is this difference?

I'll try to make this not seem difficult. First, the tire sizes. The first number is the overall width (not the width of the tread). The last number is the rim/wheel size (we'll get to that in a minute). The middle number is called the aspect ratio. In simple terms, it's the percentage of sidewall compared to the overall width (the first number). So, on the original tires, the sidewall's height is ~75% of the width of the tire. There is a very complex equation that you can calculate the overall height of the tire. Most manufacturers list that themselves because the equation is college-grade math. Now, about the wheels; since you would be going to a smaller wheel, you should see if the person who is trying to sell you this stuff would allow you to test fit one first. I know it's a lot of work, but it will be a real downer to buy them & find out that they hit the brake calipers. I would think that they should fit except that your suspension & brake parts were first introduced in 1998 models (coil spring/A-arm). The 1997 was still using the old I-beam front suspension. Those used smaller brake parts, so 15" wheels worked fine for them.

I say they will work, but like the old saying goes: An ounce of prevention is worth a pound of cure.

 

[partsguy84823]

So, metric tires 101...

The "75" is the aspect ratio of the tire. For example, the width of a 245/75R16 tire is approx. 245mm, the sidewall height (from wheel to tread) is 75% of 245mm. 245*.75= 185.75mm. So the sidewall of your tire is 185.75mm tall. Moving on. 185.75mm comes out to about 7.313in. So you have the sidewall from the ground to the wheel, the wheel, and the sidewall from the wheel to the top of the tire. (7.313+16+7.313)=30.626inches.

So your old tires are about 30.626 inches tall...

The new ones would go like this...
265*.70=185.5 //sidewall height
185.5mm = 7.303in //convert mm to inch
(7.303*2)+15 = 29.6inch //sidewall + rim = new tire height.

They will fit just fine. Good luck...

 

[partsguy84823]

OOPS, someone typed faster than me. Anyway, now you have the eqution... i don't consider it college level math. But then again, my major is Computer Engineering, so math is my friend. The 15" rims will fit just fine. Some of the 98+ Rangers came with 15" rims... I promise, you'll be fine...

 

[Machine]

Wow. That is some schooling! Thank you guys for the info. I checked it out and I will be able to test fit one just to make sure before I actually get them. So that will seal the deal if all goes well.

 

[partsguy84823]

Wow. That is some schooling! Thank you guys for the info. I checked it out and I will be able to test fit one just to make sure before I actually get them. So that will seal the deal if all goes well.

No problem buddy...

warning more math

By the way, its not a huge deal, but the new tires will be about 2.8% smaller than your old ones. This means that the will cover 2.8% less ground per rotation. Why does this matter, because your trucks speedometer and odometer work off of counting revolutions of the tires. So if for one revolution your truck thinks it has traveled 'x' feet, and because the tires are smaller it actually traveled (x-.028(x)). Then your speedometer will read 2.8% slower than your actual speed. So when your speedometer says 60mph, you are actually moving 58.3mph, and when your odometer says you went 100 miles, you actually went 97.2 miles.

The error gets larger the faster you are going...

end math

Its not enough difference to worry about, but I thought I would make you aware.

 

[partsguy84823]

By the way Machine... I just looked at your "heres my truck" thread. That interior is CLEAN!!! Nice looking truck...

 

[sccaSVT]

OOPS, someone typed faster than me. Anyway, now you have the eqution... i don't consider it college level math. But then again, my major is Computer Engineering, so math is my friend. The 15" rims will fit just fine. Some of the 98+ Rangers came with 15" rims... I promise, you'll be fine...

The equation I saw was much more technical & used these symbols: +, /, *, -, %, , , & .

 

[Machine]

By the way Machine... I just looked at your "heres my truck" thread. That interior is CLEAN!!! Nice looking truck...

Thanks. I love the truck...unfortunately living in New England it is VERY rusted up.