Will Tier 4 lead to gas tractors again?

[IndyIan]

I guess I was thinking that motors like the 1.4L ecotec in the Cruze have 90 ft/lb at 1500 rpm and 148ft/lb at 1800 to 4500 rpm and the Cruze Eco can almost match a Jetta TDi for mileage and probably has equal or lower operating costs.
But also for us weekend warriors, who may do 100-200 hrs per year, even having a 25% increase in fuel usage with a non-turbo gas engine is probably a good trade to avoid a much more expensive tier 4 diesel. $3-4k off the tractor buys a lot of gas and it would take many years for the diesels fuel efficiency to pay off.

 

[DieselMonk]

look here on Gas vs Diesel vs LPG

Estimating Farm Fuel Requirements

 

[Gale Hawkins]

Indylan while your logic is supported by the math you are forgetting that in CUT's gas vs diesel is only an emotional issue and not a technical issue.

At today's fuel prices DieseMonk's link points out there is NO fuel cost savings for diesel engines today when it comes to most any tractor usage.

Gasoline and Diesel Fuel Update - Energy Information Administration Note the fuel pump graphics at the bottom to understand why diesel fuel cost more as of last month.

 

[3930dave]

Interesting debate.

As has been pointed out, GDI and a modern diesel don't look that different, at least on the fuel input technology side. Yes, these new GDI engines are pretty impressive, on paper.

One thing I'm waiting to see more data on is how the fuel dilution plays out, real world, on these GDI motors. Decent diesel motor oil has been designed to deal with some fuel dilution for quite a while.

I suspect, but haven't checked, that some of the recent S* oil specs have changed in part to deal with gasoline fuel dilution.

The other issue that concerns me with GDI is the long OCI's that are being promoted. And, let's not forget, the ethanol content keeps rising in gas. I wouldn't call pure gasoline a great lubricant, but I'm thinking it's lubrication properties decrease, as ethanol increases.

Time will tell, but if I had to pick one engine to live with some fuel dilution in the oil, I'd pick diesel every time, over gas.

I'll be watching this with interest. We've gotten used to having the bottom ends of gas motors being pretty reliable - GDI and ethanol might preclude me buying used vehicles with this technology - at least for a generation or 3.

Rgds, D.

 

[RobertN]

With proper cam, exhaust, and valve timing, they could totally change that power curve to more of a working engine curve.

I remember seeing my Uncles Super Sport Chevelle 396, and my Grandfathers GMC truck 396 side by side with hoods up. Very different carb, intake, and exhaust(both were stock).

The carb/intake/exhaust were made to rev on the strip on that SS Chevelle. That GMC was made for grunt(which it had plenty of).

I mentioned before; look at the Farmall A/Super A motors, and in the case of what I had, a 19hp Kubota. That Farmall A was a low RPM motor, with gobs of torque, that matched up well with the motor in the B8200. And they would last forever. But, they were 2x the displacement, and would never approach the diesel on fuel consumption.

I guess I was thinking that motors like the 1.4L ecotec in the Cruze have 90 ft/lb at 1500 rpm and 148ft/lb at 1800 to 4500 rpm and the Cruze Eco can almost match a Jetta TDi for mileage and probably has equal or lower operating costs.
But also for us weekend warriors, who may do 100-200 hrs per year, even having a 25% increase in fuel usage with a non-turbo gas engine is probably a good trade to avoid a much more expensive tier 4 diesel. $3-4k off the tractor buys a lot of gas and it would take many years for the diesels fuel efficiency to pay off.

 

[Redbug]

I think you better hang on to the tractor you have now. Take care of it and you won't need to worry about tier 4 and all that. That's my answer to the problem. As you know, many people are hanging onto their older trucks because of that and used ones are getting harder to find.

 

[jimmysisson]

A mid-sixties 396 one ton on our neighbors farm would go up a good grade at 5 mph in third gear (out of four). Didn't go quick but didn't buck or rattle. Must have been turning 2-300 rpm. Plenty of low end there.
Best thing on diesel for me is engine braking in steep woodlots. I'd sure miss that. Gas would be quieter which I would like. Not about to buy new anyway but this is interesting.
Jim

 

[Ilikeurtractor]

A gas engine will never meet the power and reliably of a diesel engine. [snip]

Gasoline engines do meet (and actually exceed) the "power", if you mean horsepower. If you mean torque that is different. Most modern gasoline engines surpass diesels on a liter-for-liter horsepower basis. When it comes down to getting things done, it's horsepower that makes it happen. That being said, I'm a big fan of the diesel engine, but realize and respect this important fact about gasoline engines.

I agree on the reliability for gas vs. diesel. Getting all the horsepower from a gasoline engine means ramping up the speed and wearing things out faster. In addition, I think most people prefer operating engines at lower speeds where diesels tend to shine.

I've always wondered why diesels aren't built to allow higher revs? I know the obvious answer - it will blow up at high rpm, but why does this "have to" be? I'm guessing a high speed diesel (relative to gasoline engines) could be built, but other than component strength issues, I wonder what else would be limiting factors? Seems like having diesels that could reach rated operating speeds like gasoline engines could offer a lot more power per displacement. Maybe this is what the GDI does/attempts.

 

[Ilikeurtractor]

[snip]I've always wondered why diesels aren't built to allow higher revs? I know the obvious answer - it will blow up at high rpm, but why does this "have to" be? I'm guessing a high speed diesel (relative to gasoline engines) could be built, but other than component strength issues, I wonder what else would be limiting factors? Seems like having diesels that could reach rated operating speeds like gasoline engines could offer a lot more power per displacement. Maybe this is what the GDI does/attempts.

Sorry to veer off topic but I was thinking about this more and wondering about the tractor pull diesel engines. I really don't know much about them but heard they can run really high boost pressures but I never really knew how fast they turned. Browsing on the net I found this:

High Performance Diesels: 'Black Smoke' Tractor Pulling Market: Engine Builder

which states "The top diesel classes will run between 6,000 and 7,000 rpm, which is much more than a stock diesel tractor that may be only as high as 2,200 rpm."
The article goes on to explain the expense to do this as well as the relative limited life of such engines. I didn't see any horsepower/liter claims, but I would suspect these engines would surpass gasoline power densities. From a theoretical standpoint, diesels should have superior power densities due to the higher inherent compression ratios (or ultimate cylinder pressures) they use. I guess the long-term practical application of them changes this equation a bit.

 

[Jerry/MT]

Gasoline engines do meet (and actually exceed) the "power", if you mean horsepower. If you mean torque that is different. Most modern gasoline engines surpass diesels on a liter-for-liter horsepower basis. When it comes down to getting things done, it's horsepower that makes it happen. That being said, I'm a big fan of the diesel engine, but realize and respect this important fact about gasoline engines.

I agree on the reliability for gas vs. diesel. Getting all the horsepower from a gasoline engine means ramping up the speed and wearing things out faster. In addition, I think most people prefer operating engines at lower speeds where diesels tend to shine.

I've always wondered why diesels aren't built to allow higher revs? I know the obvious answer - it will blow up at high rpm, but why does this "have to" be? I'm guessing a high speed diesel (relative to gasoline engines) could be built, but other than component strength issues, I wonder what else would be limiting factors? Seems like having diesels that could reach rated operating speeds like gasoline engines could offer a lot more power per displacement. Maybe this is what the GDI does/attempts.

Besides the obvious effects on durability, the heavier components required for the diesel's higher pressures and temperatures mean the recipricating loads (~ rpm) are very high, and that requires adding more weight to the engine. That's not necessary bad for a tractor except for the cost implications. However, a lot of these diesels are used in trucks where added weght is a no no. So there are compromises