A small point but what you call hp-hrs really hp-hr/gal straight from the Nebraska test charts. You use the correct numbers but your labels are wrong. Does not affect your results since you are using the correct numbers with the wrong label. More important for those math folks that like the labels to fit to insure the equations are correct.
The efficiency data does not lie. I know there are those that think the Nebraska test is bogus but they never explain why or how. The Nebraska testing will explain their methods and what they indicate in the listing for most of the tractors tested. I see no reason to think their data is not accurate. The efficiency, hp-hrs/gal for the 4020 and 4040 is greater than for the D.
The Nebraska test does not always list the hp-hr/gal for their drawbar pulls but you can use the variable power data they list for a pretty good estimate. Comparing the drawbar pull at differing loads and the newer tractors still come out ahead.
If a 4020 will pull a 5-16 plow then, in your soil, I expect the D would be a 2-16 tractor. You will have to get the D and do a comparison to find out for sure.
Horsepower is horsepower, does not change with the engine type. A mower engine of 15 hp has the same horsepower as a steam engine of 15hp if, and a big if, they are measured the same way. Horsepower takes into account several factors including speed and torque so it is a good way to compare engines. It does not take into account the torque range or curve. I expect your 15 hp Reid engine would be more than 15 hp if measured using modern methods. The rpm of the engine, slow vs high speed engine, has nothing to do directly with the hp rating. I also expect the Reid engine has a very broad or flat torque curve which allows the engine speed to change a lot with less effect on the horsepower than an engine with a narrow or peaked torque curve. The large flywheel will also store power in the form of inertia and will let the flywheel power through short additional loads without needing a large input from the engine itself. A lawn mower engine does not have that large inertial mass to help it through short load fluctuations and must depend on the engine itself. I also expect the Reid engine is truly more than 15 hp.
In the end, you do not have to justify your decision to any of the YT "experts" since it is not their money nor do they know your situation. Get the John Deere D and have fun! Lots of 4040s out their, a lot less of the Model Ds still around.
Upload one or more videos to your post. Photo and video filesizes should be less than 8MB. Formats allowed are gif, jpg, png, ogg, mp4, mov, and avi. Be sure to use filenames without spaces or special characters, and filetypes of 3 digits lower case.
We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]
Today's Featured Article - Restoration Story: Fordson Major - by Anthony West. George bought his Fordson Major from a an implement sale about 18 years ago for £200.00 (UK). There is no known history regarding its origins or what service it had done, but the following work was undertaken alone to bring it up to show standard. From the engine number, it was found that this Major was produced late 1946. It was almost complete but had various parts that would definitely need replacing.
... [Read Article]
Latest Ad:
1964 I-H 140 tractor with cultivators and sidedresser. Starts and runs good. Asking 2650. CALL RON AT 502-319-1952
[More Ads]
All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy
TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.
