175 diesel fuel use
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Category: Allis Chalmers
Forum Name: Farm Equipment
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URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=121476
Printed Date: 22 Oct 2025 at 6:28am
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Topic: 175 diesel fuel use
Posted By: Nathan (SD)
Subject: 175 diesel fuel use
Date Posted: 05 Apr 2016 at 2:27pm
| I read the post about the 175 gas. 4 hrs and the tank was empty.Does anyone know why the diesel version was super fuel effecient? I think I know why, but curious about other ideas. |
Replies:
Posted By: SHAMELESS
Date Posted: 05 Apr 2016 at 2:40pm
| back then...Diesel was really, REALLY cheap to use! like .20 cents a gallon! |
Posted By: SHAMELESS
Date Posted: 05 Apr 2016 at 2:46pm
| last year was the first year since the introduction of diesel fuel in the late 1800's that the diesel was higher priced than gasoline! diesel used to be the throw away by-product when making gasoline. then someone discovered how to use this throw away product on the cheap! then the refineries found out someone was getting some use out of it and they couldn't have that! so they started charging for it, but it was still a lot cheaper than gasoline! then the refineries said that they make gas out of diesel, and that helped them drive the prices up! |
Posted By: DSeries4
Date Posted: 05 Apr 2016 at 7:12pm
Keep in mind that was under an almost full load plowing or disking. That is the reason you do not see new gas tractors. Diesels by their nature (and design) are more efficient than gassers. ------------- '49 G, '54 WD45, '55 CA, '56 WD45D, '57 WD45, '58 D14, '59 D14, '60 D14, '63 D15D, '66 D15II, '66 D21II, '67 D17IV, '67 D17IVD, '67 190XTD, '73 620, '76 185, '77 175, '84 8030, '85 6080 |
Nathan (SD) wrote:Posted By: Nathan (SD)
Date Posted: 06 Apr 2016 at 2:12pm
| Here is the answer. The perkins was rated at 75 hp at 2500 rpm. It was only working at 66% load and less in the 175. For any diesel engine, that is optimum range to maximize fuel economy. |
Posted By: BrianC
Date Posted: 06 Apr 2016 at 3:21pm
|
A few reasons. One is the diesel fuel has more energy per gallon. About 13%. The fuel is denser, there are more hydro carbons per unit volume. The tanks are fixed volume size, we purchase per unit volume. As an aside, if you loaded up by weight, with 10 POUNDS of gasoline vs. 10 POUNDS of diesel, the inherent 13% advantage would be evened out, for the most part. Another reason is the efficiency, how well the engine contraption turns the fuel into work. The diesel is better. Higher compression, usually greater expansion ration, "lean burn" at partial power output. Wikipedia says Diesels are 40-50% efficient, gas 20 to 30%. And as mentioned already, the diesel was also cheaper per gallon, this is the icing on the cake. You can see it in the Nebraska test reports. Given a gallon of fuel, the diesel got 45% better "MPG" on variable load conditions, 38% on constant high load conditions verses the gas engine. No wonder you can go all day with the diesel, but have to add fuel with the gas. Go on tractordata.com and look up power tests. Nerd it out with a calculator. You will find the 170 gas and diesels tests. That is an Allis gas motor vs the English Perkins diesel. Look up the 180, Allis gas vs Allis Diesel. Perkins wins. But then look up the Allis 6080, the Allis diesel now matches the Perkins. Usually the gas engines were quieter, lower rpm, and I value this. Mellow, vs diesel clatter. |
Posted By: rw
Date Posted: 09 Apr 2016 at 11:32am
| I wonder about the accuracy of the info the Nebraska test has published. Compare the same age brand and model of tractor and see the gas versus the diesel and when used for pto power. My non scientific observation is the gas tractors we use for chores will burn the amount gas they say and some more to boot. Our tractors are worn out and inefficient from being used 40 or more years without a rebuild. I like the gas engines for quiet combustion but they seem like they always need another tank of gas before you can do the next little thing. the big tank on the 190 XTD that does some of that work always seems like it has enough fuel left to do one more chore. |
Posted By: Eldon (WA)
Date Posted: 09 Apr 2016 at 9:02pm
You have a point there....I run my 175D a little under rated pto speed a lot of the time if the mowing is easy, around 1600 rpm. Most tractors are running above 2000 for pto, JD and Kubota run around 2500! As an added bonus if I change oil at 100 hours it is actually about 125... ------------- ALLIS EXPRESS! This year: |
Posted By: Brian Jasper co. Ia
Date Posted: 10 Apr 2016 at 6:58am
|
What the other Brian is trying to say is there are more BTUs in diesel than gasoline. The other reason is volumetric efficiency. A diesel has a higher volumetric efficiency ratio because the piston sweeps more of the combustion chamber than a gas engine, forcing more of the burned gases out on each exhaust stroke. ------------- "Any man who thinks he can be happy and prosperous by letting the government take care of him better take a closer look at the American Indian." Henry Ford |