The 3 cylinder Deere 5Es are notably larger than the Kubota
M5660SU, they are about the same size as a Kubota
M6060/
M7060 but are far heavier. A 5045E MFWD's ship weight is 5919 pounds while the
M5660SU weighs 4189 lb and the
M6060/7060 weigh 5090 lb. The Deere's loaders are stronger as well, the 520M used on the MFWD 5Es can lift about as much weight to full height as the Kubotas' LA1154s can lift to their shorter "power" position. They are also correspondingly less maneuverable. The Deere 5E is the largest tractor you'll find in the non-deluxe 50-75 hp range and the
M5660SU is about the smallest. For reference, the open station non-deluxe CNH units (NH Workmaster 50/60/70 aka CaseIH Farmall 50A/60A/70A) are physically a smidge larger than the M5560SU but weigh about as much as the
M6060/
M7060. Bottom line, if you want a smaller, lighter, more maneuverable tractor get the Kubota, if you want a larger tractor get the Deere.
Both machines are a little different than the other machines in their respective manufacturers' lineups. All Deere 5E 3 cyl tractors are the same size, can be had with the same size tires, use the same loaders, and use the same basic engine but the 5045E is the oddball as it is only available in an open station with the 9/3 TSS transmission. The other 5E 3 cyl units (5055E/5065E/5075E) can be had with a cab and/or the 12/12 PowerReverser. The
M5660SU is somewhat smaller than the
M6060 and
M7060 with a shorter wheelbase, smaller tires, weighs about 900 pounds less, and has the smaller 2.4 L engine from the L and MX line vs. the 3.3 L four in the
M6060/
M7060. It is also open station only. It has the same 8/8 hydraulic reverser as the
M6060/standard
M7060 and uses the same loader as the
M6060/
M7060.
I've run both of the Deere transmissions. Both have been around since the 1990s and have been solid units in our service. The 9x3 TSS is a very traditional gear transmission with synchronized in-range gear shifting and a mechanically clutched independent PTO. We've done a lot of loader work with a tractor with that transmission and I didn't have any trouble. You do have fewer reverse gears, but unless you're backing up with mower, you can always throttle up or down to change your travel speed to compensate for the smaller number of reverse gears. The PowerReverser is a slick transmission but probably the largest advantage of it is that it's a 12 speed vs. a 9 speed of the TSS and you get a better selection of gears for field work (C range in either is pretty much just limited to road usage.) The PowerReverser's clutch pack isn't directly clutched by your foot like the TSS's clutch plate is so clutch engagement in the PowerReverser is a little grabbier in my opinion.
A 5045E is rated at 50 engine HP and 37 PTO HP. I suspect the tractor actually makes about 44 PTO HP and possibly more. Nebraska didn't test the 5045E but they did test the others in that line, they perform PTO dyno tests, check hydraulic performance, and 3 point hitch performance. The 73 rated engine HP and 57 rated PTO HP 5075E put out 64 HP at the PTO. You can guarantee the 5075E doesn't make more than 75 engine HP as the EPA would thus require it to use DEF, so I assume the 73 engine HP is accurate. 64 PTO HP is a 14% driveline loss, and this is very close to the results Nebraska got for the other three units- the 5056E's 67 HP engine netted 60 PTO HP, and the 5055E's 59 HP engine gave 51 HP at the PTO. That would put the 5045E at 44 PTO HP if the engine isn't under-rated, and more if it is. It may very well be under-rated as the same basic 2.9 L 3 cyl engine in that tractor has been used since the 1970s and was rated at 55 HP naturally aspirated and 65-70 HP with a turbo before Tier IV. The 5045E has this engine with a turbo, rated at 50 HP. Either Deere significantly under-fueled this engine to cripple it to 50 HP or it makes more than 50 HP.
Our experience with an 8' mower is with a pull type being used with a 65 (tested) PTO HP JD 5083E and a six-cylinder New Holland with in excess of 100 PTO HP. The only time the 5083E knew it was back there was if the mower scalped and hit a dirt mound. It would lug the engine but didn't stall it. PTO was run in standard mode. The NH being run in economy PTO mode didn't know the mower was back there at all. One of my neighbors has a cabbed 5220 which is directly in between the 5045E and 5055E in terms of power with an 8' 3 point Rhino mower and it did fine doing his once-per-year field mowing. I would expect the 5045E to do okay cutting grass with an 8 footer. Worst you do is take a narrower pass or slow down. The 5E is a lot larger tractor than the 4066 mentioned above and I wouldn't put a ~1600 pound 3 point MX8 on a 4 series tractor, they are only about 3800 pounds. I would put one on a 5E though. Deere's PTO HP requirements being different for lift (full 3 point mount) vs. semi-mount or pull type is mainly to discourage somebody from putting a big heavy full 3 point mount mower on too small of a tractor. If you want to be specific, Deere publishes implement codes for its implements and tractors that let you know if the 3 point implement is too heavy for the tractor. Deere's literature says the full 3 point MX8 is fine for any MFWD 3 cyl 5E with enough
ballast (e.g. leave your loader on or use a bunch of suitcase weights), but the MX10 is too heavy, and the 3 point MX8 is too heavy for a 4 series tractor.
If you want the Deere 5055E, look for a used one with a few hundred hours. There are bunches of <5 year old 5045E-5075E tractors with <500 hours for sale. Typically these list at $30-32k for an MFWD unit with the 520M loader and a PowerReverser transmission, you can probably talk them down a little more. Prices on the 5055-5075 MFWD units are typically pretty similar regardless of power, same with any of the 2wd units. If I were you, I'd probably look at a lightly used (<1000 hour) 5065E or 5075E with your choice of transmission and know you have plenty of power for that 8' mower. I wouldn't worry about the economy PTO unless you intend to use it frequently with something really light like a broadcast spreader or a 5' cutter.
