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Discussion Starter #1
This is a really interesting vid. I've never seen a direct real-world comparison of a turbo vs a naturally aspirated version of the same tractor. These Indian dudes really love their tractors! There are a lot of Indian tractor vids on youtube.

The results are quite interesting. I imagine that though it may seem trivial to some of us, if you are disking/plowing a very large field, that 100 RPM advantage ads up to some time savings. I'd love to know what the fuel cost difference is, and whether the additional fuel used is mitigated by the time saved.

 

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Discussion Starter #2
I realize that the video may be hard to follow...but the gist of it is this:

He has two versions of the same tractor (Mahindra Arjun), one turbo, one naturally aspirated. He pulls the same disc harrow across the same field with both machines with the throttle at the PTO marked position on the tach, and notes the resultant RPM loss under full power (pedal to the floor).

The NA tractor dropped 200 RPM and slowed down accordingly.

The turbo tractor dropped 100 RPM and slowed down accordingly.

The difference is very minor, but probably significant in the long run.
 

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That's doesn't seem like much of a difference. Since the turbo is basically just adding a few HP to the engine, it seems he would be better off with a tractor that has a larger engine with more HP increase. I've had turbo vehicles in the past and it always seemed like a bit of a "cheat" instead of adding displacement. The downside to the turbo is cost and complexity.
 

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Discussion Starter #4 (Edited)
That's doesn't seem like much of a difference. Since the turbo is basically just adding a few HP to the engine, it seems he would be better off with a tractor that has a larger engine with more HP increase. I've had turbo vehicles in the past and it always seemed like a bit of a "cheat" instead of adding displacement. The downside to the turbo is cost and complexity.
Well this particular tractor only has a 10% HP increase with the turbo. So with 20% you might see a smaller drop in RPMs. But I find it very interesting that Mahindra finds even this small increase very significant. They advertise a 2.3 (or something like that) KPH speed increase (presumably while doing field work). Which may seem like nothing to most of us, but is probably quite important on a big farm where time is money. If you have 10 tractors that are spending 10 hours plowing, it would be a big deal if those same tractors would spend 9 hours plowing. That's a total savings of 10 tractor hours per day during which you could do something else. 9 tractors would then be able to do the work of 10 tractors in the same time.

But yeah, agreed, a larger engine would be better in every way except fuel economy. As far as complexity though, turbos are very simple and not prone to failure, especially in tractors with the low boosts (compared to cars). I think the only concern would be the engine itself, but it would take a very long time for the increased wear to manifest.
 

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That's doesn't seem like much of a difference. Since the turbo is basically just adding a few HP to the engine, it seems he would be better off with a tractor that has a larger engine with more HP increase. I've had turbo vehicles in the past and it always seemed like a bit of a "cheat" instead of adding displacement. The downside to the turbo is cost and complexity.
The "cheat" is the whole idea of a turbo or super charger. Stuff more air(along with fuel) into the same size engine for more power. What could possibly go wrong? :laugh:

If you are not building boost then you are saving fuel. For small 4 cylinder engines it works fairly well. My 1.4L Cruze gets 34-36 MPG on the highway and around 30 in mixed driving. However, I have heard though from more than one Ford ecoboost V6 turbo truck owner that their mileage isn't any better than the V8 it replaced, so I guess it depends on what engine you stick a turbo onto and what your intended use is. GM is getting ready to do the same thing with a turbo 4 cylinder in the 1/2 ton trucks. Recent road tests by the magazine indicate it doesn't save any fuel compared to the 5.3 V8. I think that is because the engine is a large displacement for a 4 cylinder (2.7 liter) and the amount of weight it has to haul around. So you have to ask why do it?

I agree, turbos add complexity and cost. I do like them on diesels as that is what makes the power on any modern diesel, to include my duramax. I just dread the day if it ever needs to be replaced. That will be a healthy bill.
 

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The "cheat" is the whole idea of a turbo or super charger. Stuff more air(along with fuel) into the same size engine for more power. What could possibly go wrong? :laugh:

If you are not building boost then you are saving fuel. For small 4 cylinder engines it works fairly well. My 1.4L Cruze gets 34-36 MPG on the highway and around 30 in mixed driving. However, I have heard though from more than one Ford ecoboost V6 turbo truck owner that their mileage isn't any better than the V8 it replaced, so I guess it depends on what engine you stick a turbo onto and what your intended use is. GM is getting ready to do the same thing with a turbo 4 cylinder in the 1/2 ton trucks. Recent road tests by the magazine indicate it doesn't save any fuel compared to the 5.3 V8. I think that is because the engine is a large displacement for a 4 cylinder (2.7 liter) and the amount of weight it has to haul around. So you have to ask why do it?

I agree, turbos add complexity and cost. I do like them on diesels as that is what makes the power on any modern diesel, to include my duramax. I just dread the day if it ever needs to be replaced. That will be a healthy bill.
New turbo on my 01 7.3L was just shy of $1200. I replaced it myself. Figure 6 hours R&R for a shop.
Duramax is a VGT turbo, so price will be more...
 

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The "cheat" is the whole idea of a turbo or super charger. Stuff more air(along with fuel) into the same size engine for more power. What could possibly go wrong? :laugh:

If you are not building boost then you are saving fuel. For small 4 cylinder engines it works fairly well. My 1.4L Cruze gets 34-36 MPG on the highway and around 30 in mixed driving. However, I have heard though from more than one Ford ecoboost V6 turbo truck owner that their mileage isn't any better than the V8 it replaced, so I guess it depends on what engine you stick a turbo onto and what your intended use is. GM is getting ready to do the same thing with a turbo 4 cylinder in the 1/2 ton trucks. Recent road tests by the magazine indicate it doesn't save any fuel compared to the 5.3 V8. I think that is because the engine is a large displacement for a 4 cylinder (2.7 liter) and the amount of weight it has to haul around. So you have to ask why do it?

I agree, turbos add complexity and cost. I do like them on diesels as that is what makes the power on any modern diesel, to include my duramax. I just dread the day if it ever needs to be replaced. That will be a healthy bill.
Very good points about turbo vs. no turbo. I'll share a personal experience: I have two cars, one for use in summer and one for use in winter. The summer car has a naturally aspirated 6.2L V8 and averages 25mpg. The winter car has a 2.5L 4cyl turbo charged engine and averages 24mpg.

Lot of other factors involved that are different, manual vs. auto, 2 years old vs. 14 years old, 455hp vs. 360hp etc. The summer car is fast, the winter car is quick....
 

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Discussion Starter #8 (Edited)
When you add DPFs to the mix, it gets even more complex. A failing/malfunctioning (or maybe just old!) DPF can take out your turbo, and vice versa. They are seeing this quite often on road trucks, but of course those get a lot more hours put on them than any utility tractor.

https://autotechnician.co.uk/can-a-dpf-cause-turbocharger-failure/

Another thing I wonder about as I consider my next tractor purchase (something I will do for the rest of my life! :) ) is, are tractor turbo engines built like commercial truck engines?

So in a tractor trailer, turbo engines often outlast NA engines because they are built stronger to cope with all the extra stresses of a turbo. They get hardened steel parts and other improvements, and those parts are so much better than the parts they put in non-turbo truck engines that they end up lasting longer despite turbo stresses.

So I'm wondering, does Yanmar do that with non-industrial or non-agricultural tractor engines? (e.g. CUTs) Because they have no reason to. Considering the low hours the average owner puts on a tractor engine, what would be their incentive? The commercial truck engine people have real incentives...driving those things to engine failure and rebuild is quite common considering how much they are used, so failures due to turbo stress have real costs in terms of reputation hit (which affects sales) and warranty claims. But tractors? Nah. If a tractor's turbo engine had 50% of the lifespan of an NA engine, maybe what, 1% of them would ever get there?
 
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