Diesel Cars
- Thread starter Joey D
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- GTP_Duke
Living in America, I'm not a big fan of diesel cars. They get excellent fuel economy for the most part, but:
1) they are noisy
2) they stink - the exhaust is killer
3) in small-displacement form, they tend to be weak.
Diesel engines, due to the heavy nature of their construction, tend to rev slowly and redline at a very low number. While they offer very good torque numbers, the horsepower ratings are low, and they acclerate slowly.
A giant, 1-1/2 ton duallie Ram or F350 with the big diesel will take quite some time to accelerate to 60 mph. The thing is, it can do almost the same time towing a 30-foot boat or a car trailer. They have the advantage of displacement, and that monster torque is what makes them so useful for trucks.
But in a car like a Jetta diesel, the small engine can't really take advantage of that. The only reason I would buy one is if I had a 70-mile commute each way. And even then, I'd probably just get a job closer to home.
1) they are noisy
2) they stink - the exhaust is killer
3) in small-displacement form, they tend to be weak.
Diesel engines, due to the heavy nature of their construction, tend to rev slowly and redline at a very low number. While they offer very good torque numbers, the horsepower ratings are low, and they acclerate slowly.
A giant, 1-1/2 ton duallie Ram or F350 with the big diesel will take quite some time to accelerate to 60 mph. The thing is, it can do almost the same time towing a 30-foot boat or a car trailer. They have the advantage of displacement, and that monster torque is what makes them so useful for trucks.
But in a car like a Jetta diesel, the small engine can't really take advantage of that. The only reason I would buy one is if I had a 70-mile commute each way. And even then, I'd probably just get a job closer to home.
- 2,660
a diesel engine will last as long as you own the car. im a big fan of diesels for the pulling power they have (torque). my 82 landcruiser had over 400 000km on the odometer on all original parts. give me a petrol engine that lasts that long with over 25mpg on the highway and ill lick the sweat off an albanian goat hearders nutsack.
as for accelleration, you can get a turbo diesel 454 chev for around 7000 australian that has 489hp and 562 ft/lbs on 9 lbs of boost.
as for accelleration, you can get a turbo diesel 454 chev for around 7000 australian that has 489hp and 562 ft/lbs on 9 lbs of boost.
There is great misconception and misinformation floating about concerning diesel engines. First of all, diesel engines are no heavier than petrol engines. Their low-rev-happy nature is due to the nature of diesel fuel: it has a low burn temperature. It burns based on compression, with no spark. This results in an engine that has a lot of low-end torque, but which quickly dies off (usually around 3,000rpm). Turbo-diesels are popular, helping to spread the torque curve somewhat.
And while a diesel's standing start may be unimpressive, a diesel can out-acclerate its compartively rated petrol brother at speed. Catching up in the petrol car requires dropping a gear and then revving higher. Assuming the two cars have equal "horsepower" ratings, the diesel's torque will always be higher. This forces a change in your method of driving, should you want to move swiftly. Your shifts are based on the torque peak, not on the power peak.
The best comparison is Peugeot's RC concepts: RC Spades and RC Diamonds. One petrol, one turbo-diesel. Both have the same HP rating. Both performed nearly identically, despite one being diesel. Why? The diesel had twice the torque of the petrol. You shift earlier in the rev range in the diesel, but taller gearing meant it accelerated just the same.
http://www.ultimatecarpage.com/frame.mv?file=car.mv&num=1257&left=
http://www.ultimatecarpage.com/frame.mv?file=car.mv&num=1258&left=
Don't get me wrong, I'll probably never buy a diesel. I like hearing my engines sing to well over 5,000rpm (or 7,000, should I be so lucky). But don't base your opinions on diesels on the crap that American auto makers deliver. Here, gas is cheap. Half of all new cars (not trucks: cars) in Europe are diesel. They're not as noisy, not as stinky, and not nearly as boring as the crap we're stuck with.
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- GTP_Duke
I'm not referring to American diesel cars, which are not worth even considering. I'm referring to European diesel cars in America, such as Mercedes TDs and others. To me, they are still noisy and they still stink. I've also spent a little time in England, and the European versions are noisy and stink (to me) as well.
You are largely correct in what you say, Hooligan, but I stand by my original statement to some extent: diesels typically run a minimum compression ratio of 14:1; some get over 20:1. Gasoline engines usually run 9:1 to 11:1 or so; 12:1 is considered high. Having had both kinds of engines apart, I can tell you that the internals of a diesel are heavier to withstand the extra strain. This leads to higher rotating mass and slower revving - in addition to the less-explosive nature of diesel as you have already mentioned.
You are largely correct in what you say, Hooligan, but I stand by my original statement to some extent: diesels typically run a minimum compression ratio of 14:1; some get over 20:1. Gasoline engines usually run 9:1 to 11:1 or so; 12:1 is considered high. Having had both kinds of engines apart, I can tell you that the internals of a diesel are heavier to withstand the extra strain. This leads to higher rotating mass and slower revving - in addition to the less-explosive nature of diesel as you have already mentioned.
GilesGuthrie
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Sorry Duke, but I have to disagree. In particular where you said that the European diesels are the worst. Perhaps it's to do with the size of the vehicles, but in small hatches (like a Golf), then diesel is absolutely the way to go. As Hooligan says, a diesel car with the same max power figure as its petrol brother will be significantly quicker in the real world, but will return 10 - 15mpg more.
The Euro diesels, particularly those from the German manufacturers are stunning. They're quiet, and with the drive-by-wire throttles they don't smoke and they don't smell. The balancer shafts take the the vibrations out.
It always used to be that the six-pot engines were great, but the four-pots were rough - particularly the 90bhp lump in the Jetta that Streetracer780 mentions. Now, however, the four-pots are picking up too. I drove a BMW 320d, and while I din't particularly like the car, the engine was great. The VW Group's PD engine and the Ford TDCi engine are both excellent.
Diesel is the way to go. In the short term at least.
The Euro diesels, particularly those from the German manufacturers are stunning. They're quiet, and with the drive-by-wire throttles they don't smoke and they don't smell. The balancer shafts take the the vibrations out.
It always used to be that the six-pot engines were great, but the four-pots were rough - particularly the 90bhp lump in the Jetta that Streetracer780 mentions. Now, however, the four-pots are picking up too. I drove a BMW 320d, and while I din't particularly like the car, the engine was great. The VW Group's PD engine and the Ford TDCi engine are both excellent.
Diesel is the way to go. In the short term at least.
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I didn't say they were the worst, Giles - I said the American automotive diesels were the worst. But I was referring to the European-designed cars that I have experienced in America. I'm not impressed by the performance of those I've ridden in (which are few, at least few built in the last couple of years).
Perhaps I am just sensitive to diesel smoke, but the streets of London were much harder on my eyes and throat than most American cities are.
Perhaps I am just sensitive to diesel smoke, but the streets of London were much harder on my eyes and throat than most American cities are.
Most gas stations have diesel, which is also cheaper than regular fuel.
I don't have the time to get into diesel cars right now, but America shys away from them because America is largely ignorant to alternative cars. Largely.
Ride in a diesel Jetta wagon - it's slow. Not VERY slow, but slow enough to notice the difference.
- 1,838
Get a diesel if you want economy.
A new Opel Astra(I don't know if you can get it there) with Euro 5 spec diesel engine can manage 4.8litres per 100 KM. So, in Malaysia the price of diesel is about RM0.78cents per litre(divide by 3.8 and you get the figure in US dollar). I don't know how much diesel cost in the US but I'm sure it'll save you a LOT of money and there isn't smoke to boot.
But that is for mother nature's sake. If you want to be a bad boy, get a monster F-350 or even better, a kick-ass 8 litre Viper that uses petrol faster than I piss.
A new Opel Astra(I don't know if you can get it there) with Euro 5 spec diesel engine can manage 4.8litres per 100 KM. So, in Malaysia the price of diesel is about RM0.78cents per litre(divide by 3.8 and you get the figure in US dollar). I don't know how much diesel cost in the US but I'm sure it'll save you a LOT of money and there isn't smoke to boot.
But that is for mother nature's sake. If you want to be a bad boy, get a monster F-350 or even better, a kick-ass 8 litre Viper that uses petrol faster than I piss.
Joey D
Premium
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Well to make money I buy cheap cars and fix them up then sell them. So I'm always looking at AutoTrader so I'm always finding deals. Plus, I don't want to be boastful here,but my family is rich, not snouty rich but rich.
Also I'm one of those guys who hates driving the same car for very long. If I woulda keep the Eclipse it wouldn't have ran here during the snow season.
Also I'm one of those guys who hates driving the same car for very long. If I woulda keep the Eclipse it wouldn't have ran here during the snow season.
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