245/70/19.5 or 285/70/17 ?

[ERoss]

What would be the advantages and disadvantages of these two tire/wheel

combinations? What gear ratio would work best with each combo 3. 73 or

4. 10 when used with the 48re auto transmission. I'm so confused please help!

 

[EricBu12]

I am getting the 245's you list. It is similar in diameter as the 285/75-16 but skinnier. So that means it will be lower RPM's when driving. I have a 6 speed so it is not as much problemactic. I like the 245's as the weight is at 4080# per tire on the 12 ply.



I think the 285/70-17 would be a step up from the 285/75-16 but I think it is not as wide. I would go with the 245's or if you want to retain the ratio, go with 225/70-19. 5 Will be the same diameter as the 265-16 but like 9" wide.

 

[Beast2B]

the first number 245, 265, 285 is the section width in mm (tread width is SLIGHTLY less because of sidewall bulge). 65,70,75 is the aspect ratio (the sidewall is 75% of the section width, etc). Obviously, the last number is the wheel diameter. The 285/70-17 and 285/75-16 are almost identical in overall height, the one inch wheel diameter difference is negated by the change in aspect ratio. The best source for size is the manufacturers website, or from the dealer you're purchasing them from.

Height is the only factor that will affect the odometer/speedometer, width will not. Also, remember that a high load range tire will ride like crap on an empty truck without changing the tire's air pressure as load changes, not too tough but maybe you'll never use a load range G tire's capacity. also, make sure your wheels meet the specs for the tires you're selecting, most are limited by air pressure. ... or maybe they look cool! (major factor in my selection!)

 

[JCastilleja]

I've put 285/75R17s on my truck and it performs good for my driving style. If you will not be doing a lot of off-road driving where you may want to lower air pressure (such as rock/sand trails) then a thinner sidewall would be beneficial for on-road driving, especially on the curvy roads (handling). My wife has rubberbands on her wheels (245/45R17) on her car and potholes/curbs are a major concern with thin sidewalls ( blisters, cuts, etc... ) Also, cost is an issue. The bigger the wheel (19 vs 17) the higher the cost. I have BFG AT KOs with a load range D. Then again, I don't normally haul/tow heavy loads.



---As far as gear ratio, fuel economy may also be a concern. Do you more often than not haul/tow heavy loads... do you NEED to drive 75 mph with that load, these are all things to consider.



I just joined the forum so forgive me for not having a fancy signature block yet I havn't learned all the acronyms yet either! I just bought a 2500 CTD with the auto transmission and stock gear ratio. I put on a set of 287/70R17 BFG AT KO Load "D" tires on the stock wheels and a leveling kit.



Both sizes are good, just depends on what your driving needs are!



Good Luck!!

 

[Beast2B]

Welcome JCastilleja, you have the same mindset as me regarding the wheels/tires. You just said it better!

Start your sig with basics... year, body, etc and build it as you improve the truck. Also, add a location to your sig so locals can chime in, too.