Interesting comments from JD dealer

[bandit67]

So since I have some time before I'm 'allowed' to get my next machine, I've been doing a bunch of research. I stopped by a local JD dealership and then called a few days later trying to get some info out of them. Basically, I was told that for the 'homeowner' work I want to do on a 2 acre mountain property at 8500' above sea level, the smallest hydro machine I should go with is the 3520.

Apparently, the 3xxx series are too big and heavy for my elevation until I get into the 37hp turbocharged model. Also, I apparently would be very dissatisfied with the much lighter 2520 at 26.5 hp, which size-wise, is more along the lines of what I want. Now, I know a few folks up here with 770's or 790's that are plenty happy with their performance. Could it be that the hydro tranny robs the machines of that much hp?

I have had a local Kubota dealer tell me that he thinks I'd be quite unhappy with the B26 TLB with its 26 hp engine and 4000 lbs of bulk at 8500', but that machine is easily 1000# heavier, or more, than a 2520 outfitted with FEL and hoe would be.

I had a 24hp subcompact hydro at 5500', so that translates to 18 hp at sea level, and it had plenty of power for its size, even to run the 60" MMM in tall grass. At 8500', the 2520 would equate to about 16 sea level hp, and weighs maybe 500 lbs more than my sub did. Back in 1991, I used a 14hp Yanmar compact gear tractor at sea level that was the same size as the 2520, and never found it to be lacking power.

So, either the salesman is trying to get me to buy a bigger, more expensive machine (which I'm not going to do), or he really is telling the truth that JD doesn't have a machine that would suit my needs, and the 2520 would be seriously lacking power at 8500' above sea level. He's basically saying that I'd probably only be happy with 30hp in a machine the size and weight of the 2520, which narrows the field to only Kubota offerings. Now, I don't really have a problem with that, but I wonder if you JD folks think I should take his word and just stop looking at the 2520.

 

[gordon21]

If you know people that are currently happy with a 790, then the obvious choices would a 790 or a 990. The 990 might be over kill for 2 acres.

Check around to see if there are any rental places that have a 790 or 990. You wouldn't need to rent one. The mere fact that rental yards have them would speak pretty loud. If they don't have them, what models do they have? You could check other cities within 300 miles that are the same elevation.

 

[putt_putt_green]

From what I understand, Turbos make a huge difference at higher elevations due to the lack of oxygen. You may want to do a search on turbos at higher elevations.

 

[bam747]

I'm confused about your math...

You said you had a "24 HP subcut @ 5500 feet which translates to 18 HP at sea level". You are also saying the 2520, rated at 26.5 HP at sea level "would equate to about 16 sea level hp". Your math seems to be reversed.

The general rule about naturally aspirated engines is that you LOOSE 3% of your sea level HP per 1000 feet of elevation.

This means the 26.5 gross HP 2520 (rated at sea level) will produce about 22.1 gross HP at 5500 feet or only 19.7 at 8500 feet.

HP @ Elevation = HP @ Sea Level * (1 - (.03 * Elevation in Feet/1000))

For practical purposes, turbo charged engines loose very little horse power due to elevation.

The bottom line is that if you think a naturally aspirated "X" gross HP tractor will meet your needs, but you live at significant elevation, just remember that you automatically loose that 3% per 1000 feet of your sea level HP for a naturally aspirated engine.

If you do not have the option of turbo charged 26.5 gross HP engine, and "need" that 26.5 gross HP at your 8500 feet of elevation, you'd have to buy a naturally aspirated 33.3 gross HP tractor.

And guess what the gross engine HP rating is on the 3320? Yep, 32.5 gross HP. But, the 3320 is NOT turbo charged, so it is effectively only 24.2 gross HP at 8500 feet.

The next step up is the 4520, which is turbo charged, and will therefore maintain most of its rated 37 gross HP even at 8500 feet!

The bottom line is that if you think a "naturally aspirated 26.5 gross HP" tractor of ANY COLOR will do what you want at 8500 feet, they will all have the same relatively poor performance due to the altitude.

 

[bandit67]

OK, so I clarified the 16 sea level hp of the 2520 in my original post - that would be at 8500'. What I've heard out here is more like 23-25% loss for every mile above sea level, so I was rough guestimating that I'd be down about 40% off of rated hp at 8500'. If I used the 3%/1000', that would put the 2520 at 19.7 hp.

I would THINK that 26 hp would be enough for an 1800 lb +/- machine, but according to the JD dealer, it won't. Lots of FEL work, some box blading, maybe 2 or 3 times per year field grass mowing, backhoe work, etc.

My main point was that a 14hp machine worked well for me at sea level years ago, a 24hp machine worked well at 5500' (my calcs say it equated to 18hp, but the 3%/1k' equates to 22 hp). If a 27 hp gear machine suffices at 8500', does the hydrostatic transmission steal that much power that a 26.5 will be unacceptable? How much power does the hydro rob?

The 790 is not an obvious choice because I want a hydro - gear is a bit tiring after a long day on a hilly property, and I'm not getting younger. I know because I've spent a couple of days using a gear drive rental on the property.

Putt-putt - I am well aware of the benefits of turbos at altitude, and that even a particular turbocharged engine will react very differently at altitude than at sea level, which is why I own a turbo diesel pickup instead of a gasser. And turbocharged engines do lose quite a bit of power at elevation compared to the same turbocharged engine at sea level, though no where near as much as a normally aspirated engine does.

I really don't want such a big machine as the 3520. I think I've found a couple of models of 27 hp turbo charged compacts, but they are from manufacturers with a much smaller distribution chain - I'd rather stick with a brand that is well represented in my area that can get me parts and warranty service within a reasonable amount of time.

If the 26.5 hp 2520 won't quite cut it, then I have to go with a 30hp model in the same size category from another mfr. But if the 2520 would do fine at 8500', then there are a number of models I can look at in that size-weight-power range.

 

[jcmseven]

Bandit,

Here is the scoop. I live at 4000'; and the top of my mountain, where I work a lot is 6300'. My 3720 laughes at this. My 4310 was laughed at on this, really struggling. My 4520, no problem. A 4115 I tried before going with the 4310, no problem. Any of the following will be fine: 2520, 3520 or 3720 would all do fine. Although the non-turbo 2520 will lose some power at altitude, it will not lose that much and will still have a favorable power to weight ratio a fact confirmed with the 4115 I used, which had 2 less horsepower and roughly the same chassis weight. I do not know if where you live is also steep or just high plateau, but as you can see we have both. 25 percent grades (or more) and some height, although slightly less than you have. This places more of a strain on the machine than does altitude and the turbo machines are better, but a small frame with high power such as the 2520 would be OK. I think the salesman is trying to get you into a more pricey machine than perhaps you want.

John M<

 

[RollTideRam]

I have done all the work you mention with a 2520. I'm at about 750' above sea level. I never ran out of power, in fact I did everything but bush hog at about 1600rpm. I used the bush hog at 2400rpm in stuff as tall as the back tires. You will probably stay in low range if it is that hillly, but the tractor will work, in my opinion. I traded my 2520 for a 3320 mainly for the loader capacity and the fancy seat. JC

 

[swines]

Go buy the Kubota. Their horspower is probably completely different than everyone elses...but, if it was me - I'd get a turbo for that altitude. If you try running a rotary cutter in tall grass or brush - you'll be cursing the person that convinced you to go with a smaller tractor... and, the hydro probably takes about 1/2 hp...away from PTO.

 

[ducati996]

You high altitude guys, I tell ya - makes for good training before climbing Everest -

I would just require a demo between machines to be sure -its the only way

 

[hemiguy]

Bandit

Too bad Deere no longer has an equivalent for the excellent 955. It would fit your needs perfectly at about 2000lbs (without attachments) and 33hp. The 3x20's, are about 3000lb and, from what I can see, have higher center of gravity - not an advantage if your property is very hilly.

I know you're looking for new, but a nice low hour 955 would have everything a 2520 would have +6.5 hp more. But, they don't sell cheap from what I've seen. I really think Deere needs a 30+ hp small frame tractor to compete with the Kubota B3030 and B7800.

With all of that said, I've found (at about 500ft around here) that my 2520 never lacks for HP when doing ground engaging and loader work but could usually use more traction. I have 240LBs of wheel weights but might eventually put fluid in the tires.

Good luck in your tractor search