wendell wrote:
I have never raced the two, but by nature diesels are slower than gas. the hemie will out run the cummings, fords v-10 will out run the power stroke. I would put my money on the 3.7, I don't know how much of a hp advantage a diesel would need to out run it's gas counter part, but more than the crd offers I'm afraid. Torque doen't win races, hp does, unless maybe your racing the 1/8 mile or shorter. I think the 3.7 would even take it off the line. I'm not knocking diesels, but fast and diesel don't really go together, thier not made for speed. Diesels are quicker than they use to be, but beating a good running gas engine, I have my douts. I don't even like diesels, thier noisy and slow, any fuel savings they offer is deleted at the pump as diesel cost more than gas. Not to offend anyone, but diesels never turned my crank.
No offense taken, but many of your complaints about diesels are based on older technology and not on what is in the CRD. The HP complaint being valid, but fixable, however.
My take on the CRD vs the 3.7:
The stock CRD has problems with its software that keep it from pulling right off the line (retards fuel). If you power brake it, then it will eat your tires for lunch-- laying down around 25ft of rubber in 2wd-- with the EPS off, or course. When power braked, It will launch you quite quickly. Otherwise the 3.7 murders it off the line-- until around 25mph. Others have stated that the CRD is about even with the gasser on 0-60 times, My seat of the pants feel suggests that is accurate.
At highway speed the CRD accelerates like a bat out of blazes. With the gasser rental I had, you have to flog it to get it to move the way the CRD does with minor throttle input. The gasser has a delay while it downshifts and the RPM spikes before it starts really moving, the CRD moves right away. Reports do show that the 3.7 will top out higher (on the flats) by a few mph than a CRD, as that is when the lack of HP takes it toll on the diesel. The CRD will always spank the 3.7 uphill, when towing, or at high altitude (turbo vs. normal aspiration engines). I have seen what a CRD going up a hill can do-- there is nothing stock in its wieght/displacement class that will touch it going up the hill. I ate an H3, a Lexus suv thing, several lifted full size gas trucks (Chevy and the beloved Hemi Ram) and even kept the BMW X at bay until the twisties. Those engines have HP, but not enough torque to rev high enough to get to them when under load. The CRD says, no problem... what hill?
My take on Diesel Performance:
Keep in mind the above experiences are with my motor stock, versus the rental libby I had stock. Every performance nut knows that you don't buy an engine and keep it stock if you want performance-- the same is true with the diesels.
Spend $600 on a performance chip and you can take a 5.9 Cummins and beat the living snot out of a 5.7 litre hemi-- even modded ones. The quote above concerning the gas engine options being faster does not hold when you factor in vehicle mods. In fact, then the opposite is true. No gasoline burning otto cycle block modified to its maximum can ever put out more hp or torque per displacement than a diesel modified to its maximum... thermodynamic laws dictate that. The reason gassers are faster stock is because the diesel comes from the factory tuned for efficiency and the gassers for speed, not because the diesel has no potential to deliver. Diesel performance is, however, in its infancy, but is growing at an incredible rate.
The fastest truck on the planet is currently the Banks Sidewinder-- powered by a Cummins at 222 mph and street legal.
The Audi diesel R-10 V-10 is winning every endurance race it enters-- replacing the previously dominate Audi R-8 gaser. It has more hp and torque and gets better mileage than what it replaced. It is litterally blowing away the gas powered competitors. A R-10 led the field that whole race at LeMans and set several records including fuel efficiency and longest distance covered.
The Cummins 5.9 and DuraMax 6.6 are routinely modified to get over 600hp and over 1000 foot pounds of torque-- without going into the block. With fuel injection mods and nitrous-- 750+HP and 1400 foot pounds are not unheard of out of these motors. And Nitrous does not damage a diesel the way it does a gasser. Good luck getting the same hp, let alone torque, out of a 5.9 stock hemi without popping the lid off it and replacing half the motor and boring it out.
The reasons behind diesel's peroformance advantage over gas are two fold:
1. You simply cannot push as much air and fuel into a gas engine as you can an equivalent turbo diesel-- the gasser will self destruct as the pre-ignition of fuel before spark ignition destroys the motor. Diesels are compression ignited and do not have to worry about pre-ignition. The turbodiesel can be boosted and fueled until it comes apart, which in the case of CAT's used at tractor pulls-- means the sickest horsepower/torque numbers you have ever seen from a internal combustion motor of the given block size. It is not uncommon for those CAT's to have the top ends of the engine welded and clamped so that over 300psi+ of boost can be pushed through the block without blowing the headgasket. When the motors run... they sound like a cross between a diesel and a jet engine.
2. Diesel fuel has 30% more BTU's available than gasoline-- meaning you get more power per cubic inch than you could ever get by buring gas. Higher octane gas does NOT have more BTU's available-- it just resists pre-ignition better. Octane has nothing to do with BTU's. Most gas block racers go to some other fuel to try and overcome the limitation of gasoline. Consider that Jet Fuel is often though of as a high power fuel... it is essentially kerosene-- which is essentially diesel No. 1. Diesel No. 1 has less BTU's than No 2 diesel, but it has a freeze point friendlier to aircraft that operate at high altitudes and that is why it is used.
My take on diesel value:
Right now diesel is around .50 cents more a gallon, but so you know, diesel is usually cheaper than gas. What has happened over the past year is termed by the oil industry as a diesel price "inversion". This usually only occurs for a few months during the winter. With the amount of diesels being sold worldwide, it may become normal, however. Even at the current price difference it costs me about 2 bucks less per 500 hundred miles (at 27 miles per gallon in the CRD versus 21 in the gasser) to operate my vehicle. If I want, I can make my own fuel (biodiesel) out of waste vegtable oil for a $1.00 a gallon-- plus highway tax (if I'm honest and don't want to go to jail or have my vehicle impounded). For the $2000 diesel premium I also got a better trannsmission and a better transfer case. Diesel engine longevity of 250,000 to 300,000 miles out of light duty diesel's is the usual, even with modified performance motors that are sensibly driven. You don't get any of that with a gasser. Driving my diesel 300 miles uphill (many grades over 6% and some at 8%) pushing the pedal down on every grade and at an average speed of 80 overall (90+ on the steep uphills) with the ac on and bikes stapped to the back and the inside loaded with camping gear/ammo netted me 21MPG, not something a 3.7 would have done!
My take on "Smelly"
The smell in diesel was sulfur. I say was, because as of the middle of last month it has been removed from most highway diesel per the EPA (The new maximum is 15 ppm versus the old of 500 ppm).
You can smell nothing with the new fuel in newly designed motors such as the CRD. It produces no visible emissions. With the older diesel fuel, particularly a batch of cheap crap... it would emit white smoke under WOT. But never gray or black smoke. No smoke with the new fuel... and no smell in the fumes. It puts out less pollution than gassers with the exception of NOx and particulates... but that is fixed as of 2007. Better emission systems made possible by the fuel change will enable new 2007 year diesels to emit far less pollution than gassers. In fact, running biodiesel-- a 2007 vehicle will produce emissions that are safe enough that you can actually inhale them (after cooling of course, would not want to burn your mouth on the tail pipe).
My take on "Noisy"
Mine is noiser... now that I put a louder, freer flowing muffler on it. Even now, at cruise you cannot hear the motor with the radio on at low volume. At idle you can barely hear it. Under WOT, you will know its there! That is usually the first time passengers notice it. Then they tell me something is wrong with my car... that it sounds almost like a diesel.
The CRD, and other new diesel motors, are not the same old diesels that were designed 20 years ago that everyone thinks are "slow and smelly". You can find more info here:
http://www.bankspower.com/Tech_todaysdiesel.cfm
http://www.audi.com/audi/com/en1/experi ... 0_TDI.html
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