Tractor Data would have the specs for them.  D19 gas drinks fuel like no other from what I understand.  D17 is plenty of horse for hay unless you have real big hills or are putting a round baler behind it.  19 is quite a bit bigger.  I love my 17.

AaronSEIA

What sort of hay operation? Small squares D17 would probably work depending on what you're using to cut your hay,large rounds

D19 would be the way to go.

Well I'll throw my 2 cents worth in if you're wanting to stay with an older AC tractor I'd go with a 185 really good on a baler and other PTO equipment because of the hydraulically

engaged PTO and all around nimble tractor for its size.For me baling with a tractor that  has to be stopped and the PTO

mechanically engaged is aggravating after using one that can be engaged on the go.I use my 185 and Olivers 1650,1600, 1550 to bale with as the PTO on all those tractors can be engaged on the move smoothly.

vyvyjim wrote: I've heard the same thing about the d19 sucking gas, however checking tractor data it produces about the same number of horsepower per gallon as the d17. Could it be that the gas tank on the d19 wasn't sufficiently large needing to be refilled often giving the illusion of sucking gas? How big was the d19 gas tank?

D17 has 19 gallon tank and D19 has 25. Every big gas tractor sucks gas and IMO Deere was the worst. Doing light work, I'm sure a bigger heavier tractor like a D19 will take more fuel than the lighter D17. Doing heavy work, not so much difference.

I own both tractors and used to farm exclusively with them both back in the late 1980's and early 1990's and for doing tillage, even with matched equipment foe each tractor I'd take the D19 over the D17. For most small jobs I still like the D19 over the D17 although the D19 can be a little more clumsy at times and the hydraulics are the worst Allis ever built.

For me the D19 just could not get stuck in mud. I farmed an 80 acre farm that was very wet (never again!) and got stuck lots of times but almost every time, if I unhooked the disk or plow I was able to drive out. Dad's 190XT was done and finished and needed a pull when it got stuck in mud.

My old E Gleaner was another one that was nearly impossible to get stuck. Might not go straight ahead but ahead it would go. Man those were bad days, especially 1990, 1992 and my last year farming that wet ground, 1993. My best years there were the drought years of 1988 and 1989.

Or any Deere from that era,I'll say for the size tractor and what it can do my D19 gas isn't any harder on gas than any other gas tractor I run.For fuel economy my David Brown tractors and the Yanmar have them all beat for the work they'll do, they are diesels.