Post by ehm8 on Jun 13, 2008 3:28:25 GMT 1
Due to fuel prices, I have been trying to study OECD and Nebraska Tractor Tests to try and work out which brands and models are the most efficient.
What I have found that it is a complicated avenue to pursue. The tractor models posted on the web from these sources, are generally for tractor models 2 years old or older. You would think that older models would give you a guide, but this isn't the case. The same engine in different tractors can be very efficient in one circumstance, but in another tractor, even in the same model range, it can be quite bad, and different year models (especially between Tier I, Tier II and Tier III).
I have found a lot of things that you wouldn't expect. Naturally aspirated models that seem fairly efficient that don't seem to be as good when turbocharged. The Perkins 4.4 litre engines in the Massey Fergusons seem to be an example of this - naturally aspirated, they have some of the best fuel consumption figures you can find, but when turbo-charged, they seem to be some of the worst. So where are the benefits of more technology? The turbocharged engines of around 4.5 litres in the 70-100hp range with all brands seem to be pretty poor for fuel efficiency, so you wonder whether they shouldn't be using small engines in this sized tractor.
John Deere are only claiming a 4 to 9% improvement in fuel efficiency with their 6030 premium series over the 6020. For all the extra gadgetry and complexity, this is rather disappointing I think, when compared to the 30% improvement in fuel efficiency and power in diesel automobiles that has been achieved with this same technology. The premium models they say are 8% more efficient than the Standard 6030s, so does this mean that even with commonrail, the Standard 6030s are possibly worse than the older 6020s?
You really have to know what you are going to be using the tractor for. PTO efficiency doesn't necessarily equate with drawbar efficiency. I compared the Case IH MXU100 with the John Deere 6320. The 6320 was more efficient on PTO but consistantly used around a gallon more on the drawbar tests, particularly at half and three quarter power. I wonder if this is possibly due to the 6320 having the PQ transmission and the MXU fixed ratio, I don't know. If you look at the OECD figures, the 2004 6320 premium used a lot less fuel at low engine revs, but strangely reached its full fuel consumption at 1600rpm and stayed level with that consumption at higher rpm. The 2003 Standard 6320 on the other hand shows brilliant g/kwhr right through its power range.
So, if you are going to use these tests to decide on a tractor purchase, you have to be very specific and make sure the model matches exactly with the one you are looking at buying. You can't assume it seems, that because an engine in another tractor or in the same tractor model but a different year model was either poor or exceptional, it is going to be the same in the one you are looking at. And you can't assume that things like turbochargers, intercoolers, and commonrail are guarantees of better fuel comsumption in tractors.
With most of the models from different brands that I am looking at buying - 4cyl 4.5 L - nearly all are new models, so it seems after all that brainstraining and research, I am really back at square one. Maybe in the end, you just go with your gut feeling, or which one looks prettiest, and if the tractor isn't satisfactory, trade it in. I think now I will be trading up instead of going for the biggest and best first up, because then hopefully I won't be stuck with a tractor if it disappointing.
What I have found that it is a complicated avenue to pursue. The tractor models posted on the web from these sources, are generally for tractor models 2 years old or older. You would think that older models would give you a guide, but this isn't the case. The same engine in different tractors can be very efficient in one circumstance, but in another tractor, even in the same model range, it can be quite bad, and different year models (especially between Tier I, Tier II and Tier III).
I have found a lot of things that you wouldn't expect. Naturally aspirated models that seem fairly efficient that don't seem to be as good when turbocharged. The Perkins 4.4 litre engines in the Massey Fergusons seem to be an example of this - naturally aspirated, they have some of the best fuel consumption figures you can find, but when turbo-charged, they seem to be some of the worst. So where are the benefits of more technology? The turbocharged engines of around 4.5 litres in the 70-100hp range with all brands seem to be pretty poor for fuel efficiency, so you wonder whether they shouldn't be using small engines in this sized tractor.
John Deere are only claiming a 4 to 9% improvement in fuel efficiency with their 6030 premium series over the 6020. For all the extra gadgetry and complexity, this is rather disappointing I think, when compared to the 30% improvement in fuel efficiency and power in diesel automobiles that has been achieved with this same technology. The premium models they say are 8% more efficient than the Standard 6030s, so does this mean that even with commonrail, the Standard 6030s are possibly worse than the older 6020s?
You really have to know what you are going to be using the tractor for. PTO efficiency doesn't necessarily equate with drawbar efficiency. I compared the Case IH MXU100 with the John Deere 6320. The 6320 was more efficient on PTO but consistantly used around a gallon more on the drawbar tests, particularly at half and three quarter power. I wonder if this is possibly due to the 6320 having the PQ transmission and the MXU fixed ratio, I don't know. If you look at the OECD figures, the 2004 6320 premium used a lot less fuel at low engine revs, but strangely reached its full fuel consumption at 1600rpm and stayed level with that consumption at higher rpm. The 2003 Standard 6320 on the other hand shows brilliant g/kwhr right through its power range.
So, if you are going to use these tests to decide on a tractor purchase, you have to be very specific and make sure the model matches exactly with the one you are looking at buying. You can't assume it seems, that because an engine in another tractor or in the same tractor model but a different year model was either poor or exceptional, it is going to be the same in the one you are looking at. And you can't assume that things like turbochargers, intercoolers, and commonrail are guarantees of better fuel comsumption in tractors.
With most of the models from different brands that I am looking at buying - 4cyl 4.5 L - nearly all are new models, so it seems after all that brainstraining and research, I am really back at square one. Maybe in the end, you just go with your gut feeling, or which one looks prettiest, and if the tractor isn't satisfactory, trade it in. I think now I will be trading up instead of going for the biggest and best first up, because then hopefully I won't be stuck with a tractor if it disappointing.
No difference between the 310 hp full-powershift Magnum and the older 230 hp, 4 speed powershift 824, and only a slight difference between these powershift machines, and the new 930 vario that could cruise 50 km/h at reduced rpm....