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Posted: 1/4/2012 8:46:59 AM EDT
Thinking about going from a 245 to a 265, I expect to lose a little mileage, but I was wondering if I would get longer tread life. I'm guessing it will affect acceleration and cornering also, is there any positives besides more ground clearance?

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Link Posted: 1/4/2012 8:48:51 AM EDT
[#1]
redneck factor?  Mine went up when I went from 275 to 315s.
Link Posted: 1/4/2012 8:50:06 AM EDT
[#2]
Looks, generally. It will fill the wheel well up more. I'm guessing this is going on a truck?

You probably won't notice a longer tread life, in my experience. It has more to do with your driving habits and tire maintenance than the size.

Also, you probably won't see a mileage change, if your driving habits stay the same. That small of a size increase will probably gain more mileage from taller tires (effectively the same as using a taller rear end gear), than you will lose from the increased rolling resistance. You're probably still going to be within the optimum range for your rear end gears with that tire size.
Link Posted: 1/4/2012 8:53:26 AM EDT
[#3]
I'd expect to gain MPG on the freeway and loose it in stop and go. Effectively you are going to a higher gear ratio.

Also, your odometer will be off, and recored fewer miles (perhaps an advantage when you sell). But you will also be driving faster then the speedometer indicates. You can fix this with a different speed gear, if the difference warrents it (most likely the difference is so small it doesn't matter).
Link Posted: 1/4/2012 8:59:49 AM EDT
[#4]
Going from a 245 to a 265 only changes the width of the tire. It will not affect your odometer/speedometer. Bigger contact patch on concrete=more drag=potential for less MPG.  Some wheelwells are tight with factory tires, so double check for clearance.
Link Posted: 1/4/2012 9:00:49 AM EDT
[#5]
Quoted:
I'd expect to gain MPG on the freeway and loose it in stop and go. Effectively you are going to a higher gear ratio.

Also, your odometer will be off, and recored fewer miles (perhaps an advantage when you sell). But you will also be driving faster then the speedometer indicates. You can fix this with a different speed gear, if the difference warrents it (most likely the difference is so small it doesn't matter).


Actually I think the speedometer can be corrected by a programmer.



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Link Posted: 1/4/2012 9:01:55 AM EDT
[#6]
Quoted:
Going from a 245 to a 265 only changes the width of the tire. It will not affect your odometer/speedometer. Bigger contact patch on concrete=more drag=potential for less MPG.  Some wheelwells are tight with factory tires, so double check for clearance.


Wrong. If you don't reduce the aspect ratio (the 2nd number in the tire size) the overall diameter will be larger and it will affect your speedometer on a vehicle that can't be corrected via the ECU. If you increase your tire width you need to reduce your aspect ratio to keep the overall diameter the same of what you currently have.

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=25
OP just browse around tirerack. They have a ton of tech information.
Link Posted: 1/4/2012 9:02:29 AM EDT
[#7]
Quoted:
redneck factor?  Mine went up when I went from 275 to 315s.


WTF kind of car do you have that you can use 315s on?
Link Posted: 1/4/2012 9:03:59 AM EDT
[#8]
245 and 265 refers to the width of the tire. Since we don't know what the % is (245/65 for example)  we dont KNOW that he is only changing width. If we are comparing 245/65 to 265/65 then yes his tires are going to get taller. 65% of 245mm is the sidewall height.

edit: crownvic beat me to it.
Link Posted: 1/4/2012 9:04:37 AM EDT
[#9]
Quoted:
Quoted:
redneck factor?  Mine went up when I went from 275 to 315s.


WTF kind of car do you have that you can use 315s on?


Definitely not a car.

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Link Posted: 1/4/2012 9:05:16 AM EDT
[#10]
Depending on your overall measurement of the tire you might gain .5 to 1 inch in height.  This would be of value for someone that is offroading and wanted a little more clearance for the axle.  Also with a taller tire you might be going wider which would give you more traction over the surface area.  When I bought my jeep I went from a 255 to a 285 and gained almost 2" in diameter with about 1" in height.  And your speedo will have to be reprogammed.  Mine reads 2 miles slower than what I'm really going.  I haven't had it changed, but I should, as it could affect air bag deployment.
Link Posted: 1/4/2012 9:06:30 AM EDT
[#11]
OK, 245/70R17 to 265/70R17 hope that clears up any confusion.

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Link Posted: 1/4/2012 9:06:52 AM EDT
[#12]
Better ground clearance. The change in MPG and speedo will be too small to notice.

If you are really anal about it you can have your mechanic go into the computer and change the tire size / final drive specs so your speedo and everything will be correct. Depending on the OBD system it only takes a min or two.
Link Posted: 1/4/2012 9:08:01 AM EDT
[#13]
Yeah before this thread completely derails into derpdom the OP should tell us what the vehicle is, current wheel/tire on it and what he is trying to accomplish.
Link Posted: 1/4/2012 9:09:31 AM EDT
[#14]
Quoted:
Quoted:
Going from a 245 to a 265 only changes the width of the tire. It will not affect your odometer/speedometer. Bigger contact patch on concrete=more drag=potential for less MPG.  Some wheelwells are tight with factory tires, so double check for clearance.


Wrong. If you don't reduce the aspect ratio (the 2nd number in the tire size) the overall diameter will be larger and it will affect your speedometer on a vehicle that can't be corrected via the ECU. If you increase your tire width you need to reduce your aspect ratio to keep the overall diameter the same of what you currently have.

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=25
OP just browse around tirerack. They have a ton of tech information.


Awesome! I didn't know that aspect was a percentage of width. Learn something new here everyday. Thanks
Link Posted: 1/4/2012 9:11:36 AM EDT
[#15]
Quoted:
OK, 245/70R17 to 265/70R17 hope that clears up any confusion.

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Stock Tire - 245/70R17...................Search Tires Tire 1 - 265/70R17        

Section Width:9.64 in245 mm..........Section Width:10.43 in265 mm

Rim Diameter:17 in431.8 mm...........Rim Diameter:17 in431.8 mm

Rim Width Range:6.5 - 8 in..............Rim Width Range:7 - 9 in

Overall Diameter:30.50 in774.7 mm..Overall Diameter:31.60 in802.64 mm

Sidewall Height:6.75 in171.45 mm...Sidewall Height:7.30 in185.42 mm

Radius:15.25 in387.35 mm...............Radius:15.80 in401.32 mm

Circumference:95.81 in2433.5 mm..Circumference:99.27 in2521.4 mm

Revs per Mile:681.9.........................Revs per Mile:658.2

Actual Speed:60 mph100 km/h  

Speedometer1:57.9 mph96.5 km/h

Speedometer Difference: -Speedometer Difference: 3.600% too slow

Diameter Difference: -Diameter Difference: 3.49%

Link Posted: 1/4/2012 9:12:50 AM EDT
[#16]





Quoted:



OK, 245/70R17 to 265/70R17 hope that clears up any confusion.





Posted Via AR15.Com Mobile



The 70 is a % of the width. Thus, the new tire will also be slightly taller than the old even though the number stayed at 70.





 
Link Posted: 1/4/2012 9:17:43 AM EDT
[#17]
Quoted:
Yeah before this thread completely derails into derpdom the OP should tell us what the vehicle is, current wheel/tire on it and what he is trying to accomplish.


06 Durango, it came with 245s, but 245s and 265s are both OEM sizes, just curious if there would be any advantage to the larger tires.


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Link Posted: 1/4/2012 9:27:00 AM EDT
[#18]
It will be 2cm wider or about the width of a finger (hypothetically).  This will depend on if you are switching to another model/brand.
Link Posted: 1/4/2012 9:28:01 AM EDT
[#19]
Oops! That's actually 245/70R17 and 265/65R17, is that still the same rim width?

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Link Posted: 1/4/2012 9:31:57 AM EDT
[#20]
Quoted:
Quoted:
redneck factor?  Mine went up when I went from 275 to 315s.


WTF kind of car do you have that you can use 315s on?


An 8800 lb Dodge.
Link Posted: 1/4/2012 9:33:02 AM EDT
[#21]
Quoted:

Quoted:
OK, 245/70R17 to 265/70R17 hope that clears up any confusion.

Posted Via AR15.Com Mobile

The 70 is a % of the width. Thus, the new tire will also be slightly taller than the old even though the number stayed at 70.
 


That.

As far as tread life, every tire model has a tread wear rating.  Some are made of harder rubber, thus have a higher tread wear rating.  Some made of softer rubber, thus lower treadwear rating.  Tread wear rating, proper alignment, and routine rotation, will have the most impact on tread life.
Link Posted: 1/4/2012 9:34:28 AM EDT
[#22]







Quoted:




Oops! That's actually 245/70R17 and 265/65R17, is that still the same rim width?
Posted Via AR15.Com Mobile




You can't tell that by the sidewall numbers.  However the tire specs given by the manufacturer should list a wheel size range.





Also with your modified profile number, the wider tire will be nearly the same overall diameter as the old skinnier one.
 
Link Posted: 1/4/2012 9:36:03 AM EDT
[#23]
It really depends. On my old diesel truck with 4:10 gears going from a 245 (WTF Dodge?) to a 295 really brought down the RPM's at highway speed and helped with fuel mileage considerably. In essence is changed the gear ratio closer to the 39x range IIRC which made sense when I wasnt towing heavy. For a "normal" vehicle not set up to tow its really going to be a crap shoot. Your mileage will probably be either the same or worse due to having to give more gas to get up to speed. Also consider extra brake pad and rotor wear along with front end wear from having to maintain a larger, wider, and heavier tire.
Link Posted: 1/4/2012 9:39:44 AM EDT
[#24]
Quoted:

Quoted:
Oops! That's actually 245/70R17 and 265/65R17, is that still the same rim width?

Posted Via AR15.Com Mobile

You can't tell that by the sidewall numbers.  However the tire specs given by the manufacturer should list a wheel size range.

Also with your modified profile number, the wider tire will be nearly the same overall diameter as the old skinnier one.
 


Also might want to check the tire size specifications on the sticker inside the door jamb.  If his truck has that size listed as an option, then you know you're good to go.

Otherwise, worry about rubbing the frame/wheel wells when the suspension is compressed and/or you are turning the wheel from lock to lock.


Link Posted: 1/4/2012 9:39:54 AM EDT
[#25]
Time to end the speculation. Values are in mm.

           
Control     P245/70R17x8  Width 258, OD 776, section height 172
Tire 1       P265/65R17x8  Width 272, OD 776, section height 172
Tire 2       P265/70R17x8 Width 272, OD 804, section height 186



Link Posted: 1/4/2012 9:52:05 AM EDT
[#26]
Quoted:
Oops! That's actually 245/70R17 and 265/65R17, is that still the same rim width?

Posted Via AR15.Com Mobile


OP I have a 200 Dakota Quad cap and did just what you did.

I had 255/65R15 and went with 275/60R15s similar overall height and no speedometer issues.

I DID NOT like the way the tires would strongly pull the steering wheel in ruts at stoplights.  The road noise was increased.  The tires were extremely difficult to get to wear evenly.  The solution was to lower the tire pressure to <20 PSI or the center tread would wear EXTREMELY FAST.  This results in shit gas mileage.  The handling was better, but not enough to offset the negatives.

DO NOT FO.

If your desire is increased handling, go with a lower profile (the 70) to get less sidewall flex.  You will get crisper turn in and less of a ballooning type ride as well as less outside corner wear as the sidewall is stiffer and does not roll under as much.  I suggest a 55 or 60 series profile.

What is it you were desiring to improve?
Link Posted: 1/4/2012 9:57:35 AM EDT
[#27]
Quoted:
Quoted:
redneck factor?  Mine went up when I went from 275 to 315s.


WTF kind of car do you have that you can use 315s on?


Link Posted: 1/4/2012 10:02:12 AM EDT
[#28]
Quoted:
Time to end the speculation. Values are in mm.

           
Control     P245/70R17x8  Width 258, OD 776, section height 172
Tire 1       P265/65R17x8  Width 272, OD 776, section height 172
Tire 2       P265/70R17x8 Width 272, OD 804, section height 186



http://i184.photobucket.com/albums/x166/CnAPhot/tires.jpg


That's downright impressive!

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Link Posted: 1/4/2012 10:08:51 AM EDT
[#29]
What motor you have? If it's not a V8 you'll suffer more MPG and power loss than a bigger motor which you will only barely notice.
Link Posted: 1/4/2012 10:16:02 AM EDT
[#30]
Quoted:
Time to end the speculation. Values are in mm.

           
Control     P245/70R17x8  Width 258, OD 776, section height 172
Tire 1       P265/65R17x8  Width 272, OD 776, section height 172
Tire 2       P265/70R17x8 Width 272, OD 804, section height 186



http://i184.photobucket.com/albums/x166/CnAPhot/tires.jpg


Ok Mr. Know-it-All.   My car came stock with P265/35R/19s on the rears.  I just bought P275/35R/19s as replacement tires as I understand that it is the max width without having issues with rubbing (2011 M3 with ZCP).  

Can you please give me a chart showing the difference in size?
Link Posted: 1/4/2012 10:31:27 AM EDT
[#31]
Quoted:
Quoted:
Time to end the speculation. Values are in mm.

           
Control     P245/70R17x8  Width 258, OD 776, section height 172
Tire 1       P265/65R17x8  Width 272, OD 776, section height 172
Tire 2       P265/70R17x8 Width 272, OD 804, section height 186



http://i184.photobucket.com/albums/x166/CnAPhot/tires.jpg


Ok Mr. Know-it-All.   My car came stock with P265/35R/19s on the rears.  I just bought P275/35R/19s as replacement tires as I understand that it is the max width without having issues with rubbing (2011 M3 with ZCP).  

Can you please give me a chart showing the difference in size?


What is your rim width?
Link Posted: 1/4/2012 10:39:14 AM EDT
[#32]
Quoted:
Quoted:
Quoted:
Time to end the speculation. Values are in mm.

           
Control     P245/70R17x8  Width 258, OD 776, section height 172
Tire 1       P265/65R17x8  Width 272, OD 776, section height 172
Tire 2       P265/70R17x8 Width 272, OD 804, section height 186



http://i184.photobucket.com/albums/x166/CnAPhot/tires.jpg


Ok Mr. Know-it-All.   My car came stock with P265/35R/19s on the rears.  I just bought P275/35R/19s as replacement tires as I understand that it is the max width without having issues with rubbing (2011 M3 with ZCP).  

Can you please give me a chart showing the difference in size?


What is your rim width?


Rear Wheels - 19x10" ET25 (25mm offset)
Link Posted: 1/4/2012 11:26:42 AM EDT
[#33]
Quoted:
Quoted:
Quoted:
Quoted:
Time to end the speculation. Values are in mm.

           
Control     P245/70R17x8  Width 258, OD 776, section height 172
Tire 1       P265/65R17x8  Width 272, OD 776, section height 172
Tire 2       P265/70R17x8 Width 272, OD 804, section height 186



http://i184.photobucket.com/albums/x166/CnAPhot/tires.jpg


Ok Mr. Know-it-All.   My car came stock with P265/35R/19s on the rears.  I just bought P275/35R/19s as replacement tires as I understand that it is the max width without having issues with rubbing (2011 M3 with ZCP).  

Can you please give me a chart showing the difference in size?


What is your rim width?


Rear Wheels - 19x10" ET25 (25mm offset)


OEM's spec tire widths to a maximum grown in service size.  This accounts for manufacturing variability and stretching of the tire over time.
When looking at the maximum size that will fit, this  max. grown dimension MUST be used, or problems will happen later on.  When I design a tire clearance envelope to determine if there are proper clearances to the wheel arch liners, suspension components, and body structure, I'll take the max. grown section profile of a tire, sweep it left and right, then move it to the jounce and rebound positions.

The 275/35R19 generated section profile below is a max grown size for comparison.  The chart shows the difference between a design nominal tire and a max. grown.  These values are standard T&RA P-metric sizes.

The sidewall delta will be be 3mm closer to the arch liners, and the tread will be 3mm closer to the top of the liner.  Note that this 3 mm larger section radius is a free, unloaded radius at the top of the tire.  The difference in static loaded radius (SLR) at the ground will be a bit smaller.







Link Posted: 1/4/2012 11:33:52 AM EDT
[#34]



Quoted:



Quoted:

Yeah before this thread completely derails into derpdom the OP should tell us what the vehicle is, current wheel/tire on it and what he is trying to accomplish.




06 Durango, it came with 245s, but 245s and 265s are both OEM sizes, just curious if there would be any advantage to the larger tires.





Posted Via AR15.Com Mobile
Yea, but is the optional size 265/65 or 265/70?  If /70, then it came from the factory with a different spedo calibration.  





 
Link Posted: 1/4/2012 11:49:57 AM EDT
[#35]
Quoted:
Quoted:
Quoted:
Quoted:
Quoted:
Time to end the speculation. Values are in mm.

           
Control     P245/70R17x8  Width 258, OD 776, section height 172
Tire 1       P265/65R17x8  Width 272, OD 776, section height 172
Tire 2       P265/70R17x8 Width 272, OD 804, section height 186



http://i184.photobucket.com/albums/x166/CnAPhot/tires.jpg


Ok Mr. Know-it-All.   My car came stock with P265/35R/19s on the rears.  I just bought P275/35R/19s as replacement tires as I understand that it is the max width without having issues with rubbing (2011 M3 with ZCP).  

Can you please give me a chart showing the difference in size?


What is your rim width?


Rear Wheels - 19x10" ET25 (25mm offset)


OEM's spec tire widths to a maximum grown in service size.  This accounts for manufacturing variability and stretching of the tire over time.
When looking at the maximum size that will fit, this  max. grown dimension MUST be used, or problems will happen later on.  When I design a tire clearance envelope to determine if there are proper clearances to the wheel arch liners, suspension components, and body structure, I'll take the max. grown section profile of a tire, sweep it left and right, then move it to the jounce and rebound positions.

The 275/35R19 generated section profile below is a max grown size for comparison.  The chart shows the difference between a design nominal tire and a max. grown.  These values are standard T&RA P-metric sizes.

The sidewall delta will be be 3mm closer to the arch liners, and the tread will be 3mm closer to the top of the liner.  Note that this 3 mm larger section radius is a free, unloaded radius at the top of the tire.  The difference in static loaded radius (SLR) at the ground will be a bit smaller.
http://i184.photobucket.com/albums/x166/CnAPhot/tires/sizecapture.jpg
http://i184.photobucket.com/albums/x166/CnAPhot/tires/265x35.jpg







Sweet.  You da man.   The replacement tires are Michelin Super Sports which are supposed to have much better traction than the original tires the car came with.  So it looks like more surface area on a better tire.  Hopefully I won't get as much tire spin when doing launch control.
Link Posted: 1/4/2012 11:55:35 AM EDT
[#36]
Generally going up in tire QUALITY negates any advantage of adding only a little bit of width.  If you go up but keep the OA diameter the same while getting a better product, you're pretty much only still making yourself feel better about it.  Nothing wrong though if it looks a little better or the tire size is more common and sometimes cheaper, it's not that much to really make a difference if either choice is the same good tire.  Still within the specs of the wheel.  Again, better tires make a big difference, far more then a little extra tread on the ground.  I don't think any aspect would really change unless you upped the diameter. There should be plenty of room in the wheel well for the tiny bit of width difference, its not exactly uber-tight dimensions like an M3 or 911 series.
Just be aware, a lot of larger retailers today won't sell you tires out of OEM spec sizes.  Costco being one of them.  Personally I would just get better tires in the same OEM size, going from something like General to Michelin will make a HUGE difference.
 
Link Posted: 1/4/2012 12:13:41 PM EDT
[#37]
I went from bananaskin 245s to nice meaty 265s on my 2500 Suburban.She looks better,sits higher, has a tiny bit more ground clearance, and with a big block, I haven't noticed any real mileage, or rpm difference.My truck looks a lot better with the new bigger sneakers.As has been mentioned, bigboxes like wallyworld and costco will not mount them.Wallyworld (in my area) was willing to mount them on the rims, IF I brought them bare rims, and not at a discount.
 Long story short, you're going to have to go to a tire sales place.Good luck.
Link Posted: 1/4/2012 12:44:32 PM EDT
[#38]
I'm running 285s on my FJ and will probably move up one size when it comes time to replace them. (I do 5 tire rotations so all get used and all get upgraded when the time comes.)
Link Posted: 1/4/2012 1:03:34 PM EDT
[#39]
Advantage?  Ground clearance.

Link Posted: 1/4/2012 1:11:07 PM EDT
[#40]
I my car it made the spedo closer to accurate.  The car does not drive as well.  Not bad but noticeable.
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