37" tires on a 2.3l manual. Initial observations

tstarks

A couple days ago I decided to go ahead and pull the trigger on addending 37" tires on my 2.3l manual Badlands non sas, with about 6500 miles on it. I did not go with the wheel and tire upgrade when I originally ordered the bronco.

I decided to go with the Nitto trail grappler mt 37x12.50r17lt. I decided to keep my stock wheels, I like them.

A couple months ago I had added the bronco buster purch collar lift/level, 2 1/4 front lift and 1 1/4 rear lift. These are advertised as allowing you to add 37s to a badlands.

Shortly after I had received my bronco back in December, I had added 1 1/2 inch wheel spacers.

I decided to purchase the rough country tailgate reinforcement, spare tire relocater and the 3rd break light relocater brackets. Totaling about $240.

First thing I noticed was the enormous weigh difference from the old BFGs to the new nittos, not a huge surprise with the 4" plus hight difference and the 2.5 width difference plus the new tires are 10 ply.

First thing we did was remove the crach bars on the front end, of course we had to remove the front bumper to remove the front crash bars.

I wanted to run the new tires without the wheel spacers, to reduce the poke of the wider tire. We discovered that we could not, due to the tire hitting the upper control arm, at 1/2 of the stearings full turning radius. I believe this is due to the 2 1/2" wider tire. I think I can add narrower spacers and still be OK.

After completing the installation I took it for a drive. The louder road noise was the first thing I noticed, based on the tire tread not on the size.

Performance reduction was the next thing I noticed. I felt the road though the steering quite significantly, again this could be contributed partially to the aggressive tread pattern of the nitto. I also noticed at 60mph my rpms ran about 3 points lower. I found myself needing to shift down more often when going up hill. Before the change, I could set the cruse controle at 60 or 65 mph and not have any power loss up hill. Now I have to shift down to keep the set speed. MPGs is also taking a significant beating. At 6500 miles I was getting about 19mpg. I am finding it marching down quickly. Not sure where it will finally settle, as I've only driven it about 75 miles since the change.

Overall, I like the look and the increased clearance. I do anticipate the off-road perform e to be much better. The on-road performance is a little concerning as this is my daily driver. If it was mostly an off-road use vehicle, I would be less concerned.

Before
After

Shoresy

It does look great.
Did you do any speedo calibration? If so, what did you use?

When I put 35 on my MT, my Speedo is about 3% off (2mph @65) as measured with iPhone app.

Doesn’t bother me too much but remind myself when pushing the limit that I’m moving a little quicker than indicated.

And the calculated mileage will be off approximately the same percentage.

Jakob1972

Dang it do look good though.
How much more weight are this 37 over the 33s? Adding unsprung weight will affect your ride quality. I think when I was looking at 37’s the BFGs in a37 were only slightly heavier than the 35 Goodyears on the Sasquatch. That make a 37 that is not an E load range tire so they are lighter. You might try those at your next tire change to see if it makes a difference.

Sulley

A coilover lift would give you better control over your ride quality, as you’ve already compromised it a bit with the spacer lift. That might make a good next stage for you. Radflo’s adjustable would probably be good for you, or Icon given the height you need.

You’d be a lot safer throwing out those wheel spacers and going with a zero offset wheel. You’ve already compromised safety enough by removing the crash bars. Best you can hope for is to control your scrub and improve your handling with the right wheels and the coilovers I mentioned (will improve handling over the lift spacers)

Ballsy to run Nittos on a DD 🤣

RagnarKon

Part of me really wants to do this, but given I live in southern New England (the land of no off-roading)… it’s a nearly 4 hour drive to the nearest trail that would require 37s.

I’m not one who cares too much about fuel economy (I did buy a brick on wheels after all)… but thinking about the MPG hit makes me grimace a bit.

tstarks

Anyone know that the offset is on the stock wheels?

tstarks

I think a zero offset would help with the poke but without any type of wheel spacer or higher wheel offset, would cause connection with the upper controle arms again as it did on our testing.

tstarks

A couple days ago I decided to go ahead and pull the trigger on addending 37" tires on my 2.3l manual Badlands non sas, with about 6500 miles on it. I did not go with the wheel and tire upgrade when I originally ordered the bronco.

I decided to go with the Nitto trail grappler mt 37x12.50r17lt. I decided to keep my stock wheels, I like them.

A couple months ago I had added the bronco buster purch collar lift/level, 2 1/4 front lift and 1 1/4 rear lift. These are advertised as allowing you to add 37s to a badlands.

Shortly after I had received my bronco back in December, I had added 1 1/2 inch wheel spacers.

I decided to purchase the rough country tailgate reinforcement, spare tire relocater and the 3rd break light relocater brackets. Totaling about $240.

First thing I noticed was the enormous weigh difference from the old BFGs to the new nittos, not a huge surprise with the 4" plus hight difference and the 2.5 width difference plus the new tires are 10 ply.

First thing we did was remove the crach bars on the front end, of course we had to remove the front bumper to remove the front crash bars.

I wanted to run the new tires without the wheel spacers, to reduce the poke of the wider tire. We discovered that we could not, due to the tire hitting the upper control arm, at 1/2 of the stearings full turning radius. I believe this is due to the 2 1/2" wider tire. I think I can add narrower spacers and still be OK.

After completing the installation I took it for a drive. The louder road noise was the first thing I noticed, based on the tire tread not on the size.

Performance reduction was the next thing I noticed. I felt the road though the steering quite significantly, again this could be contributed partially to the aggressive tread pattern of the nitto. I also noticed at 60mph my rpms ran about 3 points lower. I found myself needing to shift down more often when going up hill. Before the change, I could set the cruse controle at 60 or 65 mph and not have any power loss up hill. Now I have to shift down to keep the set speed. MPGs is also taking a significant beating. At 6500 miles I was getting about 19mpg. I am finding it marching down quickly. Not sure where it will finally settle, as I've only driven it about 75 miles since the change.

Overall, I like the look and the increased clearance. I do anticipate the off-road perform e to be much better. The on-road performance is a little concerning as this is my daily driver. If it was mostly an off-road use vehicle, I would be less concerned.

Before
After

tstarks

Update

I have now made my once a week round trip to work and back totaling about 120 miles. Up, over and back down a winding mountain pass, with lots of hairpin turns.

I did not really feel any difference in the performance from a suspension aspect. Going around turns at speed seemed about the same, I may have even pushed it a little more than usual, to give it an extra bit of a test.

Again, the three areas of performance that I noticed the big tires having the greatest impact, was in the steering wheel, uphill power and fuel economy.

Steering

As I'm driving down the road, I'm finding that the bumps, ruts and imperfections of the highway are being felt more in the steering wheel. Again, I'm attributing this more to the grabbyness of the new tread pattern and that there is now about 20% more rubber making contact with the road.

Uphill power

Here again, on hills where before I could set the cruse control and maintain speed and rpms, I find myself having to down shift to maintain the uphill power. Just in general I'm finding I need to let the rpms ramp up higher before shifting so as to not feel the sluggishness. Here, I'm attributing this to the bigger, wider tire with the more aggressive tread pattern and weight. Obviously, if I wanted to change the gearing ratio I could alleviate some of this.

Fuel economy

Still decreasing but not at the rate it was at first. I'm currently down about .8mpg, from 19mpg to 18.2. Hopefully this will level off here shortly. The reasons for this are pretty obvious, extra weight, having to run higher rpms to maintain power and more rubber meeting the road.

Any thoughts, feel free to chime in.

AcesandEights

If you haven't calibrated your speedometer, your mpg may be off. Looks like you increased tire size by roughly ten percent, but only took a 5% mpg hit. That being said, mileage isn't great in these things anyway.

Since the downsides are several, what practical benefits have you seen off road? What were the stock tires not doing that these do?