[Torr]

Originally Posted by EfylSetaf When it comes to 25-45% of all the new cars being sold are diesel (I guess two to three years for that number), then it makes sense that 5 or so years later demand for regular gasoline will fall by 25-45%. At least. So I'm saying diesel should rise some as demand increases in the short term, when supply is changed to meet demand prices should regulate themselves into equilibrium, all else being equal. In Europe new car sales of diesels are around 60% after 4-5 years of being on the market. People point and say US gas prices are cheaper... but you can fit most individual European countries into the state I live in... my guess is we drive quite a bit more on average and are equally as sensitive to price fluctuations.

I dont think that the market penetration will be that great here if diesel goes any higher in price compared to gas. Most car companies admit that there will be a $2000 premium on the diesels. It will take 4-5 years to recoup the costs in comparison to gas driving 15k miles a year.
Although some people will not understand the inital cost difference in comparison to what they will see at the pump.

[IronStomach]

I've done the numbers many times on the gas costs... if you double your MPG from 20 to 40 mpg (which should be the very low end of mpg), and drive 15k miles a year like me, the numbers are close to a $1,200 savings... per year over five years. That's not pie in the sky, these cars are already out in Europe, have been driven through their paces, and are improving every year.

ok, assume diesel at $4.00, and gas at $3.50, 15k miles/year the difference between 20mpg and 40mpg is $1,125/year. That's based on vehicles that get 0-60 in 6-7 seconds.

[Torr]

OK, but what cars are you comparing? I figured 30 mpg for gas and 40 for diesel. Wasnt taking into account 0-60 times. Twenty to forty is a huge difference. With my calculations at the described mpg, the difference is only $250. With your calculations it still takes roughly two years to recoup a two grand premium for the diesel.

[GOTTORQ]

diesel in ct today was at 4.15 a gallon..kill myself

[IronStomach]

gottorq - nah, you can't collect your own life insurance policy or the proceeds for selling your organs on the black market to pay for the gas.

Torr - I was using conservative numbers for both. Figure 25mpg for a fun to drive, quick car - not as fast as the Mustang GT, but quicker than the V6.... I'm talking cars that won't bore you to death (as in what I've been doing?).

635d - rated at 40mpg and as fast as the M6. Granted it's pricey, sure. It still gets a combined city/hw rating of around 40mpg.
335d - same numbers really. Some early reports have hinted at more like 45mpg under speed testing. I must admit I haven't looked at BMWs in a while, I wasn't in the market for one. But These things have 300 crank horsepower and over 400 lbs ft tq at just under 2k rpms.

Both those examples are freaking expensive, but BMW tends to start new tech at the top and drop it down over time. The technology for the engines isn't limited to just them. Last I heard was VW was doing that with their entire lineup, Mercedes has three models out right now but is waiting for other manufacturers before standardizing their lineup across the nation, GM and Chrysler are going ahead with roughly half their lineup as well (for Chrysler, that's what? 2 cars now?).

With the new technology from GM and all the other manufacturers coming online in the next two years, I'd say the CAFE standards will be a joke. Expect the average model available to get 40mpg with a number closer to 70-75. Three to four years is anyone's game and economic conditions could move that bar either forward or backwards... hefty tech R&D tends to slow under really bad times and we may or may not be in really bad times two to three years from now. Leave it to the politicians and my own naive exuberance to prove me wrong.

[GOTTORQ]

lol very true..prices are rediculous tho..but screw it...its only like 40$ to fill mine anyways

[2006greyGT]

the color of diesel vs gas... what brand station do you guys find 93 octane... I only find 92 here at BP

[fosted285]

Diesel fuel is fundamentally different from gasoline all the way down to it's molecular structure. While gasoline is rated in octane, diesel is rated in cetane. All fuels start as crude oil, however gasoline is much more refined than diesel fuel. On the same token, gasoline is also much more flammable.

Gasoline, since it is ignited by a spark is required to have a low flash point and a high autoignition temperature. These numbers are -40 degrees farenheit and 475 degrees farenheit respectively. Since diesel engines rely solely on high compression to ignite the fuel mixture, the inverse is true. It needs a high flash point and a low autoignition temperature. These numbers are 143 degrees farenheit and 410 degrees farenheit respectively.

As we can see, the flash point for diesel is 183 degrees higher than gasoline but the autoignition temperature is 65 degrees lower. A reason this needs to be is as I mentioned earlier, the diesel engine runs solely off compression and as all of us who are familiar with forced induction know, as air is compressed it heats up. The extreme compression generated by a diesel engine is sufficient to ignite this fuel and that is why so much torque can be generated from such a relatively small displacement.

A vehicle powered by diesel will be approximately 20-40% more efficient than gasoline because of the amount of energy released when diesel is burnt. The specific numbers for diesel versus gasoline are 40.9 megajoules per liter and 34.8 megajoules per liter from gasoline. This is because the diesel is more dense and there are more molecules to burn. This does result in higher greenhouse gas emissions per liter, however when we factor in the 20-40% higher efficiency over gasoline, the increased emissions are negated.

The answer as to the high cost of diesel is tough and multifaceted, however I will put a few reasons out in an attempt to explain this. While diesel is easier to make and less refined than gasoline, logic would dictate that it should cost less. The problem is that no new refineries have been built in some time and the demand for all fuels only increases with time. To compound this problem, the new ultra low sulfur diesel requirement puts a strain on the existing infrastructure here and requires refittment and therefore additional expense. Last but not least, one can always chalk it up to good old supply and demand.

I hope this was useful and helpful to at least someone on here. Have a great day.

[Torr]

Good info Fosted, for those looking for the technical side. EfylSetaf- I was wondering if those cars were what you were talking about. I work at a Ford store and we also have Mazda and BMW here too. The new 1 series coupe is gorgeous and is quite powerful and gets about 30 mpg on the hwy from its twin turbo inline six. Starts at $30k too. The Mazda 3 Hatch with the regular 4 cyl 5 spd gets 22 in town and 29 on the hwy posted on sticker. Not sure what the Speed 3 gets for mileage. I just dont see the value of going to smelly diesel when it costs a premium to purchase it. I cant afford the cars that you mentioned so thats even more of a premium to pay. I am sure that in the not so distant future we will have diesel variants in the segments and cars I can afford, but unless the premium to pay is less it wont get my hard earned cash. Hopefully I am proven wrong, because we all could use vehicles that get much better fuel economy than whats on the table now. There, how was that for boring?

[Torr]

Originally Posted by EfylSetaf 635d - rated at 40mpg and as fast as the M6. Granted it's pricey, sure. It still gets a combined city/hw rating of around 40mpg. 335d - same numbers really. Some early reports have hinted at more like 45mpg under speed testing. I must admit I haven't looked at BMWs in a while, I wasn't in the market for one. But These things have 300 crank horsepower and over 400 lbs ft tq at just under 2k rpms. With the new technology from GM and all the other manufacturers coming online in the next two years, I'd say the CAFE standards will be a joke. Expect the average model available to get 40mpg with a number closer to 70-75. Three to four years is anyone's game and economic conditions could move that bar either forward or backwards... hefty tech R&D tends to slow under really bad times and we may or may not be in really bad times two to three years from now. Leave it to the politicians and my own naive exuberance to prove me wrong.

Hey I just looked at the links you provided and they are from the UK. My understand is (maybe I'm wrong here) that their formula for computing mpg is different over there. They have higher numbers than what are posted here in the USA. Also speed limits are different and this might have something to do with it. My speculation is that they base hwy mpg on maybe 50 mph versus 65 here? Dont take the numbers for fact just the difference in measurement.

[IronStomach]

Originally Posted by Torr Good info Fosted, for those looking for the technical side. EfylSetaf- I was wondering if those cars were what you were talking about. I work at a Ford store and we also have Mazda and BMW here too. The new 1 series coupe is gorgeous and is quite powerful and gets about 30 mpg on the hwy from its twin turbo inline six. Starts at $30k too. The Mazda 3 Hatch with the regular 4 cyl 5 spd gets 22 in town and 29 on the hwy posted on sticker. Not sure what the Speed 3 gets for mileage. I just dont see the value of going to smelly diesel when it costs a premium to purchase it. I cant afford the cars that you mentioned so thats even more of a premium to pay. I am sure that in the not so distant future we will have diesel variants in the segments and cars I can afford, but unless the premium to pay is less it wont get my hard earned cash. Hopefully I am proven wrong, because we all could use vehicles that get much better fuel economy than whats on the table now. There, how was that for boring?

Much less boring than me. : )

I'm with you on that though, those cars cost more than I'll spend for at least 4 or 5 years yet. Maybe I'll never buy that expensive of a car again, who can say? My only point is that when these diesels started popping up in Europe it was completely unexpected how much they would change. It made financial sense and people jumped on it.

As Fosted broke down, there shouldn't be any extra expense in physically making the diesel, just in creating new distribution for it within the US. Once there's demand for diesel, that should change and the oil companies will invest on infrastructure (if govm'ts allow it...). If it makes financial sense to Americans... we'll certainly jump on it. Maybe not immediately, durable goods purchases by families slows during recessions, but those durable goods have to be replaced after a few years.... I'm just sitting here getting excited by the technology and trying to see which way the game gets called.

Fosted, thanks a ton for the science - always fun to hear how it really works! And also thanks for keeping us on track!

[Torr]

I was looking at possibly purchasing a Super Duty Diesel for towing and mpg, but after driving one and doing the math it definitely didnt make sense financially. I was getting around 18 mpg combined city/hwy. With a F150 I can get around the same and still tow 99% of what I need to. But at $4.00 per gallon, I will just take a truck off the lot when I need to tow versus buying one.

[IronStomach]

Originally Posted by Torr I was looking at possibly purchasing a Super Duty Diesel for towing and mpg, but after driving one and doing the math it definitely didnt make sense financially. I was getting around 18 mpg combined city/hwy. With a F150 I can get around the same and still tow 99% of what I need to. But at $4.00 per gallon, I will just take a truck off the lot when I need to tow versus buying one.

Oh, yeah, the Super Duties are completely different. Those things are just plain awesome I think the diesel in that application is meant to give more torque for towing, not mileage. Remains to be seen if anything positive will come of this, I always underestimate the greed of politicians....

[Torr]

Yeah the SD's have twin sequential turbos, one for take off and the second for higher up the rpms. I thought it would make a good daily driver that I could modify for more power.