Turbo or no turbo

[RobJ]

I've never heard turbos as helping fuel econmy. That's obvious in a turbo car because your foot was always in it. And the only problems with a gas turbo was it usually was an aftermarket kit, if a gasser is designed for a turbo things tend to work out better. I recently rented a Mazda cx7 with a turbo. 4 banger and 255 hp? Didn't impress me, mileage was also poor.

Anyway on a tractor a turbo means more power, anytime you add more power you need more fuel. So IMO the 2 engines of the same displacement, the turbo is still going to use more fuel under load.

IMO, they are adding turbos to small engines these days for one reason only...cheap hp. What's cheaper, redesign a bigger engine, different internal parts even if the exterior is the same size or add a couple new manofolds, oil lines, bigger air filter and a turbo. Then you can say more hp!!

I don't have a problem with a turbo lasting a long time. They will probably need service before the engine does. But it's a coin toss I guess.

Do you really need a turbo: (JMHO here)
Doing some FEL work? No
Doing some yard mowing with a FM,? No
Taking that 12" Coastal down to 3"? No. Bahaigrass, al little harder but no.
Taking 6' Johnson grass down to 3"? Yes
Pulling a disk in 1000' rows? Yes
pulling a bottom plow in long rows? Yes
pulling a planter, No
Boxblading No
straight blading a gravel road, No

Long continious loads is where you see the benefit. If you are using foot throttle a lot, then probably not. I think they work better in a non HST tractor. To me if I buy an HST tractor I'm going to be going back and forth a lot. If I buy a gear tractor I may have large hay fields to cut, where I might not use the clutch for several hours while working. JMO.

They do have that cool turbo sound when loaded. That's worth something.

Rob

 

[N80]

I'm in the camp that less is better. In other words, if I need x number of horsepower and can get it in a simple (normally aspirated) package I'd prefer that option to an engine with a turbo that produces the same hp for the same price.

I realize diesel turbos are perfectly reliable. So are HSTs and any number of other things you can get on a tractor. I just prefer simplicity over some facets of ease of use and boosted hp. Usually 'simple' costs less and is easier to fix/work on for mere mortals like myself.

But that's just me.

Now, if I lived at higher altitudes where a turbo becomes more of a necessity, well, that's a different story.

 

[Bob_Young]

Other than vouching for their reliability, turbo usage in a diesel pickup truck isn't applicable to the OP's question. Turbos were added to diesel pickups primarily to improve throttle response and passing performance. The original non-turbocharged diesel pickups were dogs when you put your foot down. With tractors, this isn't an issue.

I think RobJ summed it up well. The turbo shines in high-demand field work. Even then, a properly sized normally aspirated engine will do the same work. For light duty tasks like loader work, chores, grading, pulling a wagon, and trimming the pasture, it's just something else waiting to fail.

But what happens if the turbocharger fails? I know of at least one Ag tractor doing field work when the turbo seized up. The help, not knowing what was going on, just opened the throttle further and worked it hard the rest of the day. When they went to fix it, the engine was a total loss. Maybe a rare occurrence, but worth thinking about if the hired help is going to work it hard.
Bob

 

[bandit67]

My response regarding the turbos in diesel pickups, along with over-the-road trucks was exactly to bring up the issue of reliablility. Overall, the turbos are reliable in those applications.

Since many tractors are nowhere near the power levels of those other engines, then it would be safe to assume the turbo failures on the lower powered tractor engines are significantly less frequent. And considering the fact that turbo usage is going to continue to increase in automobiles, the technology will continue to improve and will be around for a long time, which helps if repairs are required, even on tractors.

I would not be concerned with a turbo on a tractor engine. Probably because I have owned vehicles with turbos and don't find them as scary as folks that don't own turbos. Also, turbos on 50hp tractors should be less prone to failure than turbos on 150+ hp tractors. Turbos don't usually ruin engines when they fail unless the operator doesn't have enough sense to shut down the engine when something goes wrong, but that same logic applies to any component failure when the operator keeps going when something is wrong.

 

[DLMaine01]

I own a non-turbo tractor and am very happy with it. That said a "few" years ago(1980's) when I was in the US Army nearly all the diesels were turbocharged, trucks, apc's, and tanks. I drove a tank with a V12 twin turbo diesel and never had failure or even heard of one. I would not hesitate to buy a turbo tractor if it was what I needed.
Dave

 

[Hammy]

I've heard a few people claim that a turbo charged engine will get better fuel economy then the same hp producing engine that is naturally aspirated. To me that doesn't make sense.

The 2008 models that are being equipped with turbos, are so for emissions only. That being said, just like all the other diesel trucks and cars on the road, they are being chocked down more and more each year therefore the turbos are needed to up the hp to compensate for the power loss due to the restrictions. The fueling also has to be turned up.

Just like the 5.9L Cummins, from what I read, it was restricted as much as possible so that is why they jumped up the displacement and went to another engine.

I know the the older VW Jetta's get much better fuel economy then today's models as well as all the newer diesel trucks.

Don't get me wrong, I love the sound of my Cummins Turbo Diesel and even removed to silencer ring so I could hear that turbo whine even more but I don't understand how they (turbos) improve the fuel economy at all.

If I'm wrong, someone please explain.

Craig

 

[toddler]

The turbo doesn't add more fuel, it forces more air into the cyclinder using energy from the exhaust that would normally be wasted. More air = both more oxygen and more compression, both of which = more power/volume of fuel. The air is free, the compression energy is from the exhaust pressure which would normally be wasted, so you should get better fuel economy.

However, people need to get the engine up to speed to get the turbo pressure. so they tend to stay on the gas. Some cars with larger turbines have very little power at low revs. On a tractor, your engine rev's are usually not as variable, so I'd guess that you'll get better fuel economy.

Todd

 

[bandit67]

Hammy,

The turbocharged engine is using exhaust gas to increase engine hp. A bigger naturally aspirated engine making the same hp needs more fuel to make that hp. The bigger engine may make better power at low rpms, but the newer compound turbos are addressing that issue. You've also got to keep in mind that turbocharged engines can be a bit more "fun" to drive with the higher end power, turbo whine, etc., so drivers new to the experience tend to have a heavier foot, which in turn, burns more fuel. But if you drive both the smaller turbocharged engine exactly the same way as the bigger naturally aspirated engine, the turbocharged engine will get better fuel mileage. The benefits are significantly exaggerated at altitude.

It's not the turbo that is causing the lower mileage on the new engines. It's the additional emissions equipment causing a lot more restriction that has a huge impact on mileage on the new on-road vehicle diesels. If you think the mileage is bad now, try taking the turbo off and you'll see just how much less power there is and, in turn, because the drivers would be trying to get the power by pushing on the go-pedal even more, the mileage would be even worse.

Smaller hp tractor engines won't show as big of a fuel efficiency difference, but it is there, and can be tracked.

 

[RobJ]

Hammy,

The turbocharged engine is using exhaust gas to increase engine hp. A bigger naturally aspirated engine making the same hp needs more fuel to make that hp. The bigger engine may make better power at low rpms, but the newer compound turbos are addressing that issue. You've also got to keep in mind that turbocharged engines can be a bit more "fun" to drive with the higher end power, turbo whine, etc., so drivers new to the experience tend to have a heavier foot, which in turn, burns more fuel. But if you drive both the smaller turbocharged engine exactly the same way as the bigger naturally aspirated engine, the turbocharged engine will get better fuel mileage. The benefits are significantly exaggerated at altitude.

Sort of kinda maybe. If you are putting along in a smaller displacement turbo engine and putting along in a larger displacement natural engine, yeah the smaller displacement will use less fuel. If you are putting along the turbo isn't doing anything. The turbo needs heat to turn it faster and do it's thing. Hot gases expand faster than cold gasses.

More fuel equals more power, not more air. More air allows more fuel to be burned, thus more power. The turbo compresses more air into the cylinder, raises the effective compression, more o2 and you can burn more fuel. Same as a larger displacement natural engine pulls in more air and can burn more fuel.

There is a reason my little 3 cylinder 26hp tractor burns 1/2 gallon of fuel an hour and my BIL's Ford 6600 with a natural 80 or so hp tractor burns a couple gallons or more.

 

[Hammy]

Sort of kinda maybe. If you are putting along in a smaller displacement turbo engine and putting along in a larger displacement natural engine, yeah the smaller displacement will use less fuel. If you are putting along the turbo isn't doing anything. The turbo needs heat to turn it faster and do it's thing. Hot gases expand faster than cold gasses.

More fuel equals more power, not more air. More air allows more fuel to be burned, thus more power. The turbo compresses more air into the cylinder, raises the effective compression, more o2 and you can burn more fuel. Same as a larger displacement natural engine pulls in more air and can burn more fuel.

There is a reason my little 3 cylinder 26hp tractor burns 1/2 gallon of fuel an hour and my BIL's Ford 6600 with a natural 80 or so hp tractor burns a couple gallons or more.

Robj explained what I meant a lot better then I did. I didn't mean for it to sound like I thought a turbo helped supply diesel. I understand how they work.

I guess I'm confused in that, my MX 5000 makes 44 hp at the rear. The newer version, which is a MX 5100 is turbo charged and makes 44 hp at the rear as well. So explain how they both make 44 hp but one is choked down with emissions control stuff and then has to overpower that with a turbo. How will it get better fuel economy?

Let me throw this out there too. I don't know for sure if they share the same engine, I just assumed they do so obviously that is a big factor.