| VettePilot |
quote:
Originally posted by switch
http://world.honda.com/news/2007/40...ept-and-i-DTEC/
Also, a new 4 cylinder engine plant is being built in Alliston. Maybe they'll make some diesel engines there?
I don't know if things have changed, but being a native of Western Pennsylvania, I have reservations about diesel engines at temperatures below zero (fuel gel, etc.) -- here in Florida, it would be great.
For many years, I lived close to a commercial truck company in PA.
In the winter, at below zero temperatures, it was common to watch them tow trucks down the road to attempt to start them.
More than once, I saw them blow those large diesel exhaust stacks completely off the truck.
Many times, because of the differential action, I saw dual wheels on one side spinning backwards on bare concrete rather than the engine turning over. |
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| switch |
| I was in Eastern Europe during winter, when it was -20C, and people with diesels (there are a lot of diesels in Europe!) didn't have any problems. Even my friend in the interior, where -30C is common, doesn't have problems with his 1990 diesel Golf. |
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| rocky |
| Diesel fuel has formula changes for low temps. Given that there are many diesels in Canada, Norway, Sweden, etc etc Don't worry about diesels getting stuck with gelled fuel |
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| macphanatic |
| The problem is diesel fuel with high paraffin content. The diesel guys I know do their best to buy Sunoco diesel during the colder months. Supposedly, Sunoco has a low paraffin diesel blend that is sold in cold climates. |
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| krygny |
| Unfortunately, I doubt they'll have a 6 cyl. ready to go into the 2009 redesigned Pilot. :( |
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| GreenMachine |
quote:
Originally posted by krygny
Unfortunately, I doubt they'll have a 6 cyl. ready to go into the 2009 redesigned Pilot. :(
they are probably saving it for the second year or the refresh model. The want to have something to improve upon each year.
It's kind of like how they had LED tailights on the '07 Accord Coupe, but regular bulbs on the '08. |
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| krygny |
quote:
Originally posted by GreenMachine
they are probably saving it for the second year or the refresh model.
...
I'd rather wait 'til the second year redesign anyway. Throw in a bullet-proof CVT and ya got a deal. |
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| rocky |
quote:
Originally posted by macphanatic
The problem is diesel fuel with high paraffin content. The diesel guys I know do their best to buy Sunoco diesel during the colder months. Supposedly, Sunoco has a low paraffin diesel blend that is sold in cold climates.
See my post above. |
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| NJGuy |
quote:
Originally posted by krygny
I'd rather wait 'til the second year redesign anyway. Throw in a bullet-proof CVT and ya got a deal.
I'd be very weary of a CVT in a V6 diesel powered Pilot. I thought that a CVT's inherent weakness is propelling a heavy load. That's why you normally see CVTs on smaller cars. I think Nissan has one in the Murano mated to a 3.5L V6, but that's probably as heavy duty as they've become for regular passenger vehicles. I highly doubt we'd see a CVT in a Pilot, as heavy as it is, combined with a diesel engine and it's high torque output. A CVT would somewhat go against one of the reasons having a diesel in the first place.
That's what I think so far, unless someone could enlighten me with the latest news and technologies regarding CVTs. |
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| N_Jay |
quote:
Originally posted by NJGuy
. . .A CVT would somewhat go against one of the reasons having a diesel in the first place. . . .
Why?
A CVT's advantage is being able to more precisely match the speed/power/efficiency curve of the engine to the vehicle over a wide range of operating conditions.
The narrower power curve of a diesel generally needs more gears not less, and therefore would be better suited to a CVT (Providing one can span the necessary gear range and sustain the load.) |
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| switch |
Older CVTs, even up to a couple years ago, used chains/belts. These aren't capable of handling high torque, and is why most cars using them are small.
The newer IVT type of CVT is capable of handling high torque. Hopefully the cost of their production will make them more viable. |
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| VettePilot |
Correct me if I am wrong here, but isn't the advantage of CVT that the transmission can keep the engine in the most efficient part of the torque curve?
Something that has always amazed me is the transmission and torque converter match in my 2002 Ford Ranger -- 5 speed 5R55E automatic transmission that is not CVT.
If you hold the accelerator pedal completely steady from a standing start, it will go through all five gears without any perceptible change in rpm on the tachometer -- I've never seen any other vehicle do this.
So, it would seem that, if I knew the best rpm for torque, I could hold the transmission on that point.
Wouldn't that be just as good as CVT?
That been said, it would seem that a combination of a Continuously Variable Transmission (CVT) and Continuously Variable Valve Timing (CVVT) would be ideal. |
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| rocky |
I've driven one CVT vehicle. That was the Ford Freestyle.
The way it worked is taking the engine high up in the rev range and hold it there until you get close to the speed you asked for and then it raises the gearing. Seeing the rev counter drop as you accelerate is weird. But the 3.0 v6 was as much as a CVT could take.
CVTs are very common on low power applications MINI, European Fords Focus etc. But at the higher end "normal" boxes work best, |
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| krygny |
quote:
Originally posted by rocky
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But the 3.0 v6 was as much as a CVT could take.
CVTs are very common on low power applications MINI, European Fords Focus etc. But at the higher end "normal" boxes work best,
Not necessarily. It depends on the CVT.
Some tractor-trailers and combine harvesters have CVTs, mostly hydrostatic. Some of the largest vehicles made (earth movers and dumpers) use CVTs. I don't claim to be up on the latest CVT designs, but I think most car-based CVTs are belt-pulley type. The Subaru Justy used a metal belt that actually "pushed" rather than pulled the secondary pulley. |
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| NJGuy |
quote:
(Providing one can span the necessary gear range and sustain the load.)
I guess that was the point I was trying to come across. Traditionally CVTs in passenger cars were limited to small, lightweight cars because the transmissions could not handle heavy loads. I just wasn't sure that passenger car CVTs have matured enough to be bulletproof when applied to a diesel Pilot. I'm sure with new materials, design, and technology they've improved by a great deal. The 3900 lb. Murano uses a CVT and has a tow capacity of 3500 lbs. (I know that tow capacity also involves other factors like brakes & platform design), and I think that is pretty impressive. So maybe there's a very small chance the diesel Pilot would get one. But do you think Honda would put one there?
quote:
Some tractor-trailers and combine harvesters have CVTs, mostly hydrostatic. Some of the largest vehicles made (earth movers and dumpers) use CVTs.
I'm sure the CVT isn't new to heavy duty industrial type applications. However, for passenger cars the application of CVTs is relatively new compared to traditional automatic transmissions. It will be interesting to see how many car makers move to the CVT in the upcoming years, especially with the squeeze we might get with future fuel prices and Govt. fuel economy standards (but that's a whole other topic itself). I actually think that the CVT has a simple, practical, and yet intriguing design. But if it were up to me, I'd anger Honda accounting, marketing, and management by putting a properly designed 6-speed manual in the diesel Pilot. :)
I think all the replies I've seen so far have been both interesting and informative. |
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| PILOTinginCO |
| I thought this thread was about the "diesels coming" to the U.S. |
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| krygny |
quote:
Originally posted by PILOTinginCO
I thought this thread was about the "diesels coming" to the U.S.
Well, neither diesels nor CVTs are currently available in the Pilot, so we might as well just let the thread drift and waft and float and flutter.
How 'bout that baseball game last night. :19: |
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| rocky |
Well the Diesels are coming but right now Honda is only willing to announce them in Acuras.
http://sohc.vtec.net/news_files/732394/idtec-01.jpg
I suspect this may be just to ensure that Acura actually has something to say at Detroit. Honda after all has the Pilot/Clarity and...hmm did it show the Jazz? |
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