Tire Decisions 235s vs 245s

[Scottp528]

I just got tires installed today. Went with Falken Wildpeak AT Trail 235-65-17.

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[Jrl]

I'm interested in getting some more aggressive looking tires than the stock Continentals that come with the BS Big Bend.

I will be keeping the stock wheels as I like how they look. The two tires choice brands are the Wildpeak A/T Trail or the Open Country A/T III.

So I was set on getting the 235s, but the 245s have me intrigued. I'm thinking about doing 1.5" lift in the next few months.

So do I need a lift if I get the 245s or will I be okay for the time being? I'm not super concerned about my mpg dropping a little bit.

Or can I get the lift and have the 235s?

Thanks for your help!

-Zach

On my first edition with my factory lift I was going to try 255/70/17 anyone have any thoughts on this

 

[Bluebaru]

On my first edition with my factory lift I was going to try 255/70/17 anyone have any thoughts on this

You asked for thoughts, so here are mine. From the specs of the AT3 4S coopers, a 255/70/17 is 31.2" in dia. with an 8.3" tread width!!! No way this fits at full lock. Now, a 255/65/17 is 30.2" in dia. with an 8.4" tread width. Probably not going to clear with full lock and certainly not at full compression and full lock, unless you are willing to do some trimming of the fender liner and pinch weld. Lastly, 235/70/17 is 30.0" in dia. with a 7.7" tread width. Now you have some hope of no rubbing at full lock but when you throw in full compression??? Maybe some light rubbing???

Now compare these numbers to the universally acknowledged to fit 245/65/17's at 29.5" in dia. with a tread width of 7.9"

 

[Jrl]

You asked for thoughts, so here are mine. From the specs of the AT3 4S coopers, a 255/70/17 is 31.2" in dia. with an 8.3" tread width!!! No way this fits at full lock. Now, a 255/65/17 is 30.2" in dia. with an 8.4" tread width. Probably not going to clear with full lock and certainly not at full compression and full lock, unless you are willing to do some trimming of the fender liner and pinch weld. Lastly, 235/70/17 is 30.0" in dia. with a 7.7" tread width. Now you have some hope of no rubbing at full lock but when you throw in full compression??? Maybe some light rubbing???

Now compare these numbers to the universally acknowledged to fit 245/65/17's at 29.5" in dia. with a tread width of 7.9"

Thanks for all the data ,that is what I was lacking. Now you just sold me on the 245/65/17 on my next set . So appreciate your knowledge of those specific details .

 

[Mark S.]

I'd worry about the 1.5L having enough power to handle a 245 with aggressive offroad treads. It's one thing cruising around town and another when you are at 11,000 feet on a slippery trail. I question that the 1.5L has enough power to handle altitude and steep climbs. I wouldn't go larger than 235's for that reason. Leaving for CO for a month and I might wish I had the KO2's at some point. Decisions, decisions.

The 1.5L and the 2.0L engine options for the Bronco Sport offer an advantage over some competitors--forced induction (turbocharging). Internal combustion engines create power by burning fuel and oxygen. All other things being equal, the more fuel and oxygen you burn the more power you can make. The opposite is also true: if you reduce the amount of fuel and oxygen you will also reduce the amount of power. Cars that don't use forced induction rely on atmospheric pressure to get air into the cylinders, so the higher up in elevation you go the less oxygen you get to burn. That's not the case with engines using a turbocharger. The turbo compresses air and forces it into the cylinder (thus, forced induction) under pressure, which means it is far less affected by changes in altitude.

So, does that mean you won't lose any power at altitude? No, it doesn't. You will lose some power, just not nearly as much as an engine without a turbocharger. How much? It's difficult to be dead-on accurate, but the Owner's Manual offers a clue. In the section on towing it recommends reducing maximum weights by 2% for each 1000 ft of altitude. If you account for the increased weight of the bigger tires when loading your Bronco Sport for a day in the mountains I'd say you'll be fine using them at altitude.

 

[compass crusher]

I'm interested in getting some more aggressive looking tires than the stock Continentals that come with the BS Big Bend.

I will be keeping the stock wheels as I like how they look. The two tires choice brands are the Wildpeak A/T Trail or the Open Country A/T III.

So I was set on getting the 235s, but the 245s have me intrigued. I'm thinking about doing 1.5" lift in the next few months.

So do I need a lift if I get the 245s or will I be okay for the time being? I'm not super concerned about my mpg dropping a little bit.

Or can I get the lift and have the 235s?

Thanks for your help!

-Zach

Here's my 245 momo's. They fit great! Where I got the idea Screen shot below Built Right Industries.

 

[Bronclahoma]

The 1.5L and the 2.0L engine options for the Bronco Sport offer an advantage over some competitors--forced induction (turbocharging). Internal combustion engines create power by burning fuel and oxygen. All other things being equal, the more fuel and oxygen you burn the more power you can make. The opposite is also true: if you reduce the amount of fuel and oxygen you will also reduce the amount of power. Cars that don't use forced induction rely on atmospheric pressure to get air into the cylinders, so the higher up in elevation you go the less oxygen you get to burn. That's not the case with engines using a turbocharger. The turbo compresses air and forces it into the cylinder (thus, forced induction) under pressure, which means it is far less affected by changes in altitude.

So, does that mean you won't lose any power at altitude? No, it doesn't. You will lose some power, just not nearly as much as an engine without a turbocharger. How much? It's difficult to be dead-on accurate, but the Owner's Manual offers a clue. In the section on towing it recommends reducing maximum weights by 2% for each 1000 ft of altitude. If you account for the increased weight of the bigger tires when loading your Bronco Sport for a day in the mountains I'd say you'll be fine using them at altitude.

I've visited CO every year since 1972 and driven a different vehicle almost every year at altitude up to 14000 feet. Yes, the turbo-charged vehicles retain much more power at altitude. But, loss of power is very evident in real world, driving.

 

[Houseof7th]

You can do the 245/65r17s without a lift but there have still been a handful of claims that they will rub at full lock on the 3 lower trims (I can't substantiate those claims because there haven't been any pics of the rubbing). On a BL or FE, they fit all day long because of the .75" longer lift springs. 235s will fit all day on any trim. Don't try to go up to 245/70s as those will take some minor pinch weld and plastic trimming to fit, even with a lift.

Are you saying the 245 will fit perfectly on my badlands? I would like to upgrade my tires to the largest set possible could I go bigger? Pause!

 

[Bronclahoma]

Are you saying the 245 will fit perfectly on my badlands? I would like to upgrade my tires to the largest set possible could I go bigger? Pause!

I have 245/65/17 KO2's on my Badlands, no lift. I've never experienced any rubbing, but I've never turned full lock under maximum articulation. Driving forest roads and moderate trails, these tires have worked great for me.

 

[rdc17]

Are you saying the 245 will fit perfectly on my badlands? I would like to upgrade my tires to the largest set possible could I go bigger? Pause!

Ford says the max a BL can fit is 30.5". 245/65/17 are 29.5".

I've been running 245s for a couple weeks, no issues.

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