# What size of rear tire for a JD 3020?



## FarmerCline (Oct 12, 2011)

I'm looking to replace the dry rotted rear tires on my 3020 that I bought this past summer. It has 15.5-38s and I had planned on replacing them with a 16.9-38 as that is what the other 3020 I sold had on it. I have been thinking about it and maybe I would be better staying with the 15.5? I have been told that I'm not getting as much hp to the ground by running the 16.9 because the larger tire takes more power to turn.....does this sound right? I like the extra road speed of the 16.9 but as far as field performance which would be better?


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## Bonfire (Oct 21, 2012)

Would a 16.9 fit on that rim? My 3020 has 15.5's.


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## hillside hay (Feb 4, 2013)

I run 16.9 on 15" rim. They work nice


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## FarmerCline (Oct 12, 2011)

Bonfire said:


> Would a 16.9 fit on that rim? My 3020 has 15.5's.


 The 3020 I sold had 16.9s that were put on the original 14 inch rims and didn't appear to have any ill effects. It was kind of strange though that when I bought that tractor that it came with a set of brand new 15 inch rims......don't know why they weren't put on when they had changed tires before I purchased it. I kept the rims when I sold that tractor in case I wanted to use them on this 3020 so I do have rims if I decide to go with the 16.9s.


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## 8350HiTech (Jul 26, 2013)

Within reason, I'd always choose wider. A local guy buys and sells many of these 20 series and has told me they're always worth more with the 16.9 tires.


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## Grateful11 (Apr 5, 2009)

I tried to find it but how much taller is a 16.9 x 38 is than a 15.5 x 38". I think that's where your hit in power would come from. My late FIL bumped the 686 turbo from 15.5's to 16.9's. I never drove it when it had 15.5's on it so I have no idea what it did to the power but it's putting out 106hp at the PTO. I think the wider tires might give you a little less soil compaction and might look a little better. I'd like to put wider quad ribs on the front of the 686.


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## Gearclash (Nov 25, 2010)

I would go with 16.9s as being a better match for the tractor. There isn't really a power loss as such going up a tire size; its the change in tire diameter that affects the total gearing reduction from the engine to the ground.


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## Bonfire (Oct 21, 2012)

FarmerCline said:


> The 3020 I sold had 16.9s that were put on the original 14 inch rims and didn't appear to have any ill effects. It was kind of strange though that when I bought that tractor that it came with a set of brand new 15 inch rims......don't know why they weren't put on when they had changed tires before I purchased it. I kept the rims when I sold that tractor in case I wanted to use them on this 3020 so I do have rims if I decide to go with the 16.9s.


Then I would put the 16.9's on.


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## hog987 (Apr 5, 2011)

The only reason I see to put the smaller tires on is if your working in snow and ice a lot. Wide tractor tires suck on ice. They just slide around. Narrow tires are a bit better. But for most everything else the wider bigger tire should be better.


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## NDVA HAYMAN (Nov 24, 2009)

Hayden, I doubt if you would ever see or feel any difference with the larger tires. You know what they say, " Go big or go home". I like big tires!


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## cornshucker (Aug 22, 2011)

Definitely go with the 16.9 for lots of the reasons previously mentioned, little better traction less soil compaction. better road speed.


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## PackMan2170 (Oct 6, 2014)

I don't think that the 16.9's will be taller than 15.5's, so you shouldn't lose any HP to the ground. But if I was you I'd measure to be sure.

The only reason I ever choose a narrower tire is to fit in the furrow of row-crops better. Otherwise, I go wide; not necessarily better traction, but definitely less soil compaction and a better ride.


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## mlappin (Jun 25, 2009)

depends, a lot of the 15.5 were considered a "low profile". Kinda of a short sidewall in them if you look at them compared to a 16.9, so you would technically gain a little OD on the tire but would also gain a wee bit of ground clearance.


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## FarmerCline (Oct 12, 2011)

I just looked up the overall diameter of the tires I would purchase. The 15.5 is 61.8 inches and the 16.9 is 66.5 inches, so there is a bit of difference. These are both a Firestone radial all traction tire.


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## Vol (Jul 5, 2009)

If I was the one doing the choosing, I would want the 16.9's......kind of a industry standard and if you were selling the tractor In the future it could make a difference to some folks.

Regards, Mike.


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## barnrope (Mar 22, 2010)

For road speed and the cocky factor go with 16.9s. For yard and field usefulness go with 14.9s or 15.5s. 14.9 x 38s are actually taller than 15.5 x 38s. I have a lot of experience with 16.9 x 38 tires on the old 720 and 730 two cylinders; they pick up road speed considerably. Also have a set on my 3010. It goes so fast down the road its scary. Also the normal 5th gear for the yard is a bit too fast and gotta go down to 4rth or 3rd in the yard a lot. Not that it is bad, but just geared faster than most 4020's or 3020's I have been around. A lot of guys around here replace their 15.5 s with 14.9 s on their 560 and 450 Farmalls for a taller tire.


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## FarmerCline (Oct 12, 2011)

barnrope said:


> For road speed and the cocky factor go with 16.9s. For yard and field usefulness go with 14.9s or 15.5s. 14.9 x 38s are actually taller than 15.5 x 38s. I have a lot of experience with 16.9 x 38 tires on the old 720 and 730 two cylinders; they pick up road speed considerably. Also have a set on my 3010. It goes so fast down the road its scary. Also the normal 5th gear for the yard is a bit too fast and gotta go down to 4rth or 3rd in the yard a lot. Not that it is bad, but just geared faster than most 4020's or 3020's I have been around. A lot of guys around here replace their 15.5 s with 14.9 s on their 560 and 450 Farmalls for a taller tire.


 Yep, the 3020 I had with the 16.9s would fly down the road.....about 25 mph I think.....I did like the fact that I could go between fields faster. When I had both 3020s this past summer 8th gear in the one with the 15.5s was almost like 7th gear with the one with the 16.9s. I'm not familiar with 14.9-38s......I would not have thought that a smaller size of tire would be taller? I'm assuming it is narrower than a 15.5......I'm not really wanting to go narrower I don't think.

I got a sticker shock on the prices of a 16.9-38 today.....I could buy a 18.4-38 a couple hundred cheaper. I was told that it was a bit of an unusual size and would have to be special ordered from the factory.


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## 8350HiTech (Jul 26, 2013)

FarmerCline said:


> Yep, the 3020 I had with the 16.9s would fly down the road.....about 25 mph I think.....I did like the fact that I could go between fields faster. When I had both 3020s this past summer 8th gear in the one with the 15.5s was almost like 7th gear with the one with the 16.9s. I'm not familiar with 14.9-38s......I would not have thought that a smaller size of tire would be taller? I'm assuming it is narrower than a 15.5......I'm not really wanting to go narrower I don't think.
> 
> I got a sticker shock on the prices of a 16.9-38 today.....I could buy a 18.4-38 a couple hundred cheaper. I was told that it was a bit of an unusual size and would have to be special ordered from the factory.


Factory special order? Find a new tire dealer.

Edit: are you actually ordering bias tires? No wonder they're odd.


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## FarmerCline (Oct 12, 2011)

8350HiTech said:


> Factory special order? Find a new tire dealer.
> Edit: are you actually ordering bias tires? No wonder they're odd.


 That is what 4 different tire dealers told me. These are radials.....after having my first set of radials this summer I'm not going back to bias tires.


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## 8350HiTech (Jul 26, 2013)

FarmerCline said:


> That is what 4 different tire dealers told me. These are radials.....after having my first set of radials this summer I'm not going back to bias tires.


To be clear, I'm not saying they should be cheaper than 18.4s. Those are produced in such massive volume that they're cheaper to produce from an efficiency standpoint. I'm just saying someone shouldn't be trying to sell you on them being some sort of specialty item. Tire shops receive shipments often enough that trying to argue something has to come from the factory is a really stupid excuse.


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## shortrow (Feb 21, 2012)

8350HiTech said:


> To be clear, I'm not saying they should be cheaper than 18.4s. Those are produced in such massive volume that they're cheaper to produce from an efficiency standpoint. I'm just saying someone shouldn't be trying to sell you on them being some sort of specialty item. Tire shops receive shipments often enough that trying to argue something has to come from the factory is a really stupid excuse.


I've had to wait a day or two for tires to come from the warehouse, not a factory. Shop around hard, last set of 15.5's I bought were old stock, got a heck of a deal.


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## endrow (Dec 15, 2011)

I know some guys said when they went from 15.5 to 16.9. On an old farmall M or 656 it absolutely ruined the tractor.Gear selection was very limited back in the day you only had two years first and second that you could balel in. So you put a bigger rubber in you only had one gear and that was good for bailing .


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## FarmerCline (Oct 12, 2011)

endrow said:


> I know some guys said when they went from 15.5 to 16.9. On an old farmall M or 656 it absolutely ruined the tractor.Gear selection was very limited back in the day you only had two years first and second that you could balel in. So you put a bigger rubber in you only had one gear and that was good for bailing .


 That makes sense.....I would have a few more gears with the 8sp powershift in the 3020 but I still usually bale in 1st or 2nd. I haven't bought any tires yet but I had pretty well decided I was going to stick with the 15.5s since they are a good bit cheaper than the 16.9s. For what I'm using the tractor for(mowing, raking, and square baling) I just didn't see any advantage to going with the bigger tire except the fact that it would give me a good road gear for all the travel between fields.....15.5s are slow on the road.


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## barnrope (Mar 22, 2010)

Take a good look at the 14.9 tire. find a tractor with new 14.9 38s and compare them to 15.5s and 16.9s. They aren't a bad alternative and are between the two sizes in height.


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## Vol (Jul 5, 2009)

Nice suggestion barnrope.

Regards, Mike


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## 8350HiTech (Jul 26, 2013)

barnrope said:


> Take a good look at the 14.9 tire. find a tractor with new 14.9 38s and compare them to 15.5s and 16.9s. They aren't a bad alternative and are between the two sizes in height.


His tire shop should be able to get him the actual dimensions of all three (and also how those dimensions differ between manufacturers) without actually having to find one up close.


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## JeffMNY (Jan 5, 2014)

A friend of mine has 18.4x38's on his 3020. Has used the tractor on discbine, square baler, and manure spreader. It seems to work for him. Of course he likes big tires on everything. Guess maybe I am the same way. Put new 20.8x38's on the 856 last year and then put 18.4x34's on the 666 up from the 16.9's it previously had.


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