Is This the "Day of the Diesel?"

ruking1 · December 2006

You mentioned several reasons why the Chevy/Geo/Sprints Metro etc. was NEVER in contention with me considering the VW Jetta TDI!

But more to the point, it more than is apparent you would never be happen in a diesel. The advice is very easy and to repeat: don't get one.

goodcrd · December 2006

Double talk, double talk, double talk. That is all you give. Lets have the comparison of the 1980 Mustang 5.0 and 4 cylinder and put the VW diesel rabbit in for fun. Lets see where it goes. You brought the mustang 5.0 and 4cylinder into it, not me.

pch101 · December 2006

I would have thought that the 4-cylinder Mustang would have impressed you with its 44% fuel economy gain over the 8-cylinder version. Since performance is apparently not at all relevant to this discussion about technology, there's no need to consider it when making comparisons...right?

goodcrd · December 2006

Like I said. With you it's double talk, double talk, double talk. Put your data up and defend it, or your just here to argue. I'd like to hear your stand, it's entertaining.... right?

pch101 · December 2006

What data? You're surprised that a 2.3 liter 4-banger uses less fuel than a 5.0 liter high-output (for the time) V-8? And you're surprised that the V-8 could beat the 4-cylinder to 60 mph (or, for that matter, just about any other speed?)

Come on, seriously, this is basic automotive stuff that we're discussing here. 4-cylinder Accords and Camrys use less fuel than do higher output 6-cylinder Accords and Camrys, 2.0 liter turbo VW's get better fuel economy than do the R32 hotrods, and so on. I truly hope that you don't need a source to understand this.

goodcrd · December 2006

Your doing it again. Double talk. 1980 stats now and include the non turbo vw rabbit diesel. Are you afraid?

pch101 · December 2006

To be blunt, I'm not so much afraid as surprised.

Seriously, this is a car forum with a few car fans, right? Don't we all pretty much understand the relationship between power and both performance and fuel economy? Don't we all know that manufacturers turn to turbos so they can get more peak power out of more fuel efficient engines?

This is about as basic to things automotive as the sun rising in the east and setting in the west. We're at a pretty elementary level of discussion if all of us aren't on the same page for something as simple as this.

goodcrd · December 2006

I will be taking my CRD in for the recalls next week. I have a little over 35,000 miles on my CRD. The EGR valve was replaced at 4K. I removed the new one at 25K and inspected it. It looked fine. It was a bit hard to get to but not to much trouble if you took your time. The injectors look real easy. They have one hold down bracket with easy access to change them out. Should take no more then 15 minutes apiece to change them out. The best I got on the highway was a long trip out west. On the Oklahoma turnpike doing about 75+ mph I got 30.5 mpg with the A/C on due to being 104F outside. Love this Jeep.

goodcrd · December 2006

You seem to not understand. Look at Honda's S2000 and compare it to a turbo engine of the same size. With turbos it's all about getting as much air into the cylinder at the lowest cost. As for power it's what you want to do with it and where in the rpm band you want it produced. What characteristic are you trying to bring out? Peak power (low end or top end), Economy, or drive ability. As some posted ealier. Don't buy a diesel. So let us discuss diesels. And what about your comment that all diesels need to be turbo charged? 1980 vw rabbit diesel was non turbo. A turbo was installed for increased top end performance. Stop the double talk and stay with a point without going all over the place.

pch101 · December 2006

You seem to not understand. Look at Honda's S2000 and compare it to a turbo engine of the same size.

Argh. You do realize that if you designed an S2000 motor to work with a turbo, it would have more power with the turbo than without, right? We're talking about increasing the power of a given engine.

Displacement and horsepower are related, but the relationship is obviously not linear. But turbocharge a given engine, and it will have more power than the naturally aspirated version of the same.

1980 vw rabbit diesel was non turbo.

And it had 50 horsepower. According to this website, a 1979 diesel non-turbo Rabbit needed 21.3 seconds to get to 60 mph. I dobut that you could even buy a new compact car today in the US with times as miserable as that.

The same website claims that the 1980 Honda Civic 1.5 liter could hit 60 mph in 11.2 seconds. It also produced 33% more horsepower with a somewhat smaller motor. As slow as that is by today's standards, that is about the same as the 100hp 1.9 TDi sold by VW in the US during 2006.

goodcrd · December 2006

And what kind of mpg did they get? I understand perfectly, but you just want to argue. Where do these engines produce their hp in the rpm range? and what were they designed for? As for the S2000's engine being turbo charged so what. Could it handle the added stress? Maybe maybe not. But Honda's solution into getting more air into the cylinder was without a turbo by running the engine at a higher rpm and better intake design. It's one of the best designs out there. No turbo lag to deal with. So good power throughout it's useful rpm range.

pch101 · December 2006

And what kind of mpg did they get?

In 1982, Honda introduced a Civic that had EPA ratings of 41/55. I assume that this was probably a version of the base 1.3 liter, but with taller gearing and possibly some minor engine differences. Given that the regular Civic 1.3 55 hp car needed about 15 seconds to hit 60 mph, it's fair to guess that this one was even slower, but not as slow as the VW 50 hp diesel that needed over 20 seconds.

In any case, fuel economy could have likely improved for all of these cars by using engines with turbos that provide the same HP rating, but in a smaller package. The ability to control boost and to drive much of the time off-boost allows turbos to provide fuel savings.

As for your turbo discussion, I'm afraid to say that you've gone well adrift. Of course, there are various ways to get differing amounts of horsepower from a given displacement (the S2000 was the first naturally aspirated car to break the 100 hp per liter barrier, to choose an extreme example of maximizing power from a given displacement), but that doesn't mean that forced induction can't be used to further increase horsepower.

And since you decided to go there, the Honda offers a good example of how power and fuel consumption are related. The current S2000 has a 2.2 liter engine with 237 hp and a stick, and an EPA rating of 20/27, while the Accord has a larger but less powerful engine (2.4 liter, 166 hp) that is rated at 26/34, or 30% higher in town and 26% better on the highway. A 244 hp Accord (3.0 liter V-6) is more similar to the S2000 in fuel economy, with an EPA rating of 21/30.

goodcrd · December 2006

The 1982 Honda civic your quoting only had 67 Hp. If you used last years epa methods it would have gotten 34/43. It was built like a soda can. The most unsafe and lightest car I ever saw. My buddy put three of us in his at college and it barely moved. Honda greatly exaggerated its performance. The 1979 diesel rabbit performed better and got better FE. I had the 1979 rabbit. On the highway 46 mpg was consistant. It all depended on the conditions. Yea more power means less FE but you still are stuck in this peak horsepower non-sense. Who drives around using their engines peak hp all the time? Diesels are better due to being more efficient throughout the power band. They deliver better FE because they are much more efficient at the part of the rpm power band that the vehicle's engine normally operates. Not at peak power. And turbos are just another way of getting more air in the cylinder. That is why I brought up the S2000. And if the civic of 1882 really got 41/55 who needs the Prius. All the little subcompacts should be getting 50 mpg now. There are a lot of ways for engine to be more efficient, but at what cost? Until the EPA takes each car and drives it with a standard load across the US, I will take what they say with a grain of salt.

pch101 · December 2006

The 1982 Honda civic your quoting only had 67 Hp. If you used last years epa methods it would have gotten 34/43.

That may or may not be true, but the same EPA measurements would apply to every car fron that era, including your diesel Rabbit.

So if you compare an '82 Civic to a '79 Rabbit, the numbers are directly comparable to each other. The Civic HF achieved 41/55, while the Rabbit diesel had 40/53, which was actually slightly worse than the quicker Civic.

And if the civic of 1882 really got 41/55 who needs the Prius. All the little subcompacts should be getting 50 mpg now.

There's no reason for you to believe that. Today's subcompacts have far more power and weigh several hundred pounds more than they did 25 years ago, so their mileage should be declining. While they have been able to use technology improvements to achieve some improvements, they are offset by the greater power and weight.

At that time, a 10 second 0-60 time would have a GTI label slapped on it. Now, only a few cars, including the TDi, are that slow. You could not get away with offering a non-turbo diesel in today's market, because a naturally aspirated diesel engine large enough to generate even modest horsepower would be too heavy and large to justify using it.

qbrozen · December 2006

And in any case, are you really surprised that a 3.5 liter naturally aspirated engine with 60 more horsepower gets worse fuel economy than a somewhat less powerful 3.2 liter with a turbo? Even if the 3.2T was a gas engine, you would also expect to get better fuel economy than you would with the 3.5.

As it turns out, the E350 has a fuel economy advantage over the E550 -- the EPA city rating for the E350 is 27% higher. Again, given the power output difference between the two motors (in this case, 114 hp), why would that surprise anyone?

That's a completely nonsensical argument. The E320cdi and E350 have similar performance, as has already been pointed out to you several times (what good is more horsepower if it doesn't translate into a faster car?). The E350 and E550 don't. We're comparing 2 of the same car with the same performance (but one gets much better mileage than the other). No wonder you keep banging your head against a wall, you fail to see the obvious.

pch101 · December 2006

OK, I'm growing my hair out and putting the amp distortion to maximum. (May as well put this head banging to some use.)

Again, I can't believe that I have to go over some basic automotive principles here. So let's try this again:

-Turbocharging tends to save fuel because it allows one to use an engine that generates higher peak power, but can use that horsepower less often. It's akin to the concepts at work in both hybrids and GM's "Displacement on Demand" cylinder shutdown concept -- if you use less of the engine's potential less often, then you should get better fuel economy.

-Taking into account the point about turbocharging above, a higher horsepower engine uses more fuel than does a lower horsepower one. The production of power consumes energy.

So it's a no brainer that a higher powered naturally aspirated engine uses more fuel than a lower powered turbocharged engine, on both counts. Honestly, this is such a basic concept that we shouldn't need this many posts to discuss it, because it's obvious on its face.

qbrozen · December 2006

my cat's name is mittens.

good grief, man, why does anything you just posted matter?

The e320cdi and e350 perform the same! Why in the world do you care which has more horsepower? Are you really that insecure? Do you prefer just looking at and talking about your car rather than actually driving it?

AAAHHH... that's it, isn't it? Now I see the breakdown in communication here. I care what a car actually does! You merely care about horsepower numbers.

british_rover · December 2006

I just don't understand how he can completely ignore torque in the equation.

Torque is what gives you acceleration from a standstill and what gives you good acceleration in 4th or 5th gear without downshifting.

That is realworld performance not high rpm horsepower that is good for 1/4 mile times and overall top speed. Neither of which you are using in the real world.

pch101 · December 2006

The e320cdi and e350 perform the same!

No, they don't.

One has a turbo.

The one with a turbo has 22% less horsepower than the car without.

The one with the turbo should, when driven under typical conditions, use its horsepower less often because of the turbo.

Less power consumption = better fuel economy.

Do you really believe that power consumption and energy usage aren't related?

ruking1 · December 2006

"Do you really believe that power consumption and energy usage aren't related?"

Everybody knows and does. The ones' that do not, will ask. So perhaps you should start another threat like "those stupid enough to not know the difference are all welcomed in the PCH thread."

It is only you that doesn't see/acknowledge the utility of the matrix of trade offs. Pretty simple stuff, you dont like the trade offs? DO NOT MAKE THEM.

Again for example which you never can acknowledge, one gets 31 mpg, the other 49 mpg. Ya dont want to make a 37% savings? No problem, chose 31 mpg. Dont believe 31-49-18/49= 3? % LESS? Again, no problem. Chose the one that uses 58% more!! The market will more than accomodate you. So will the oil companies.

The hp and performance features are as easy as an A/B test, which in your case you indicate you failed to test the diesel. The torque differences are there also. All you need do is chose. Or not at all. So you can thank thread participates for saving you a gob of money and disappointment.

Now run along to a turbo thread and tell folks how they don't know SQUAT about turbo' s.

goodcrd · December 2006

"At that time, a 10 second 0-60 time would have a GTI label slapped on it. Now, only a few cars, including the TDi, are that slow. You could not get away with offering a non-turbo diesel in today's market, because a naturally aspirated diesel engine large enough to generate even modest horsepower would be too heavy and large to justify using it."

Wrong again. It's just cheaper to put a turbo on it, then put the added costs of intake and expensive cylinder head designs. But you still don't get it nor want too. I can sell you a motorized skate board also which is about the same as the 1982 civic. The skate board is safer.

"There's no reason for you to believe that. Today's subcompacts have far more power and weigh several hundred pounds more than they did 25 years ago, so their mileage should be declining. While they have been able to use technology improvements to achieve some improvements, they are offset by the greater power and weight."

This statement above is one of the very few which I will agree with. You forgot about emissions equipment. This goes the same for the diesels.

"At that time, a 10 second 0-60 time would have a GTI label slapped on it. Now, only a few cars, including the TDi, are that slow. You could not get away with offering a non-turbo diesel in today's market, because a naturally aspirated diesel engine large enough to generate even modest horsepower would be too heavy and large to justify using it. "

As I stated before that the turbo is being used more to pass emissions at lower cost then to create more top end horsepower. Not many drivers floor their accelerator to merge into highway traffic. Most even with cars capable of 0-60 times under 9 seconds take about 15 to bring their cars up to speed. So 0 to 60 times are not that important. 0 to 35 mph are more important in everyday driving. 0 to 60 times just sell cars, bragging rights!

Here is a new years resolution for you. Stop arguing for the sake of arguement. And don't buy a diesel.

ruking1 · December 2006

Just a comment from my .02 cent perspective. 0-60 might be one of the SEX items that sells vehicles. ( in the vehicle magazines) It IS/ might even be, a good objective measure. But it has ceased/or really never has been a REAL WORLD relevant tool.

I read a Corvette specific article in a Corvette magazine about a guy that has the "GREATEST 0-60 mph TEST JOB" in the world.It was about an (quick reflexed, failure) engineer for Chevrolet, that tests the 0-60 "durability", if you can call it that. The upshot of the article is the Corvette is QC'd to do 400 each 0-60, 4 second runs. Almost all OTHER cars, exotic or otherwise are NOT !! This engineer DOES have the procedure DOWN!!!! (to get 4 seconds CONSISTENTLY) Of course the article leaves out the common failures (and associated COSTS) due to this behavior AFTER 400 or so runs, but eh......maybe the 0-60 runs are a good tool to sell replacement PARTS!!!! Corporate conspiracists will love this connection eh?

One of the diesels strengths does happen to be a very respectable 45-80 mph passing measure. Hopefully I can string this parameter out for 500,000 (The VW Jetta clutch can go 400-500k with a bit of care)!

pch101 · December 2006

OK, look for my debut metal album, it will be coming out soon.

I'm surprised that the diesel fans just won't accept a basic fact that shouldn't be such a big deal -- all things being equal, diesel engines don't generate as much horsepower per liter/ci than do gasoline engines. This is just a fact, and the basic reason is because they don't reve as high. I'd relax, have a cool drink and just accept this, it's not as if it is a stigma.

Here's another real world example: the Audi R10 diesel race car that won Le Mans, compared to its predecessor, the gas powered R8 racer. They both have twin-turbos, and both have similar power (625-650 hp)

The key difference: The R8 gas engine is 3.6 liters, while the R10 diesel is 5.5 liters, more than 50% larger.

You may be noticing a pattern here -- the diesel produces less power per ci/liter than the gas engine. That margin in displacement is wide when comparing two powerplants that are both turbocharged.

The fact that the diesel needs to be larger is not a crime, it's just a reality, which makes turbocharging particularly beneficial to such engines. And accepting the fact that horsepower is beneficial to attaining high speeds does not force you to turn in your Diesel Club membership card, it's just a fact.

blufz1 · December 2006

101....... The Diesel is better for towing and lasting longer than a gasser. You don't tow so you don't know! Look at the RDX turbo for failed gasser turbo use. It doesn't get very good mileage. I would not buy it for towing.

qbrozen · December 2006

The one with a turbo has 22% less horsepower than the car without.

The one with the diesel has less horsepower, yes. And loads more torque. That's a diesel for ya.

The one with the turbo should, when driven under typical conditions, use its horsepower less often because of the turbo.

WOW! That's some logic ya got there. A car with a turbo doesn't need to use its horsepower .... alllrrighty then.

pch101 · December 2006

The Diesel is better for towing and lasting longer than a gasser.

I think that goes without saying. Torque is obviously a benefit when you are towing or carrying heavy loads, as anyone familiar with semitrucks and locomotives can attest. But they aren't necessarily very fast.

The funny thing is that I've not said a single thing on this thread that has indicated that I am opposed to diesels. I'm just pointing out that one should not make direct comparisons of 90 hp passenger cars to 180 hp passenger cars with a straight face, and that discussing fuel economy without addressing performance is not making a fair comparison.

pch101 · December 2006

You really don't understand this at all, apparently.

Pray tell, what do you think turbochargers do? I'd like to hear your explanation.

qbrozen · December 2006

discussing fuel economy without addressing performance is not making a fair comparison.

we have addressed performance ... many many times. You just dismiss it.

qbrozen · December 2006

really? you need me to explain them? you can look it up anywhere. try wikipedia. or maybe howthingswork.com. I'm not wasting space here on something so elementary.

a car can't move without horsepower. Likewise, it can't move without torque. disregarding either is a common mistake, and one that you are making.

pch101 · December 2006

I didn't ask you to look it up -- I'm quite aware of what they do -- I asked for your understanding of why automakers would be inclined to use them to save fuel.

It's pretty clear from your responses that you just don't understand why they are used, and how they save fuel compared to using larger naturally aspirated motors with similar output. What I'm saying is not at all radical, it's pretty basic and should be pretty obvious. (As I hinted before, it's the same basic premise that hybrids and cylinder shutdown systems such as GM's old 8-6-4 concept are based upon.)

hypnosis44 · December 2006

Does anyone have information on Diesel models planned for introduction in 2008?

Will the diesel be available in the 2007 or 2008 models of the Navigator or Expedition?

How about a diesel from Toyota in the Land Cruiser or LX 470?

hypnosis44 · December 2006

Another measure of motive power that avoids direct, exclusive reference to either HP or Torque alone is BMEP; Brake Mean Effective Pressure.

Possibly interesting sites:
http://www.epi-eng.com/ET-BMEP.htm

http://www.epi-eng.com/ET-Examples.htm

http://en.wikipedia.org/wiki/BSFC

The best real world performance snapshots seem to be the zero to X, X1, X2 and so on. Passing time required for 45 to 65 seems a very useful one as well. Testing standardation is always a potential problem variable, but is largely mitigated by multiple tests. In the end all that matters is real life performance, or economy, or combinations, not their claimed numbers.

blufz1 · December 2006

Go to honda uk the accord diesel is not a slug and gets 40% better mileage than the gasser. if you want to accelerate faster get the diesel civic.

qbrozen · January 2007

you keep changing the subject and avoiding points. Why they use a turbo has absolutely NOTHING to do with the simple fact that the 2 models of E-class offered for purchase here in the states accelerate the same, yet one gets far better mileage. I have never once argued the premise of a turbocharger. That has ZERO to do with the fact that YOU claim there is lost performance in exchange for better mileage in a diesel. Me and several others have continually pointed out that this is not true, at least in the case of the e-class. Why is it so hard for you to simply admit it? Who cares how its done or why its done. Its done. Plain and simple. You walk into a benz store for an e-class, and there are your 2 choices. Period. End of story. If you can't accept that, then I can't help you understand.

ruking1 · January 2007

Add to the E class the 2003 VW 1.8T, 2.0, and TDI, These three motors were used across Jetta New Beetle, Golf. A false comparison is a false comparison.

So in the case of the comparison between VW Jetta TDI and Geo Sprint/Metro, another false comparison. Fuel mileage might indeed be similar, but even "Stevie Wonder" could SEE the disconnect.

alltorque · January 2007

First off : Happy New Year to you all from here in U.K.

Just looked at the Merc UK site and get the following figures for two engines being bandied about in recent posts :

Gasser E350

272hp, 350 Nm torque @2400-4000rpm, 6.9sec 0-62mph, 29.1 mpg for European combined cycle.

Diesel E320

165, 540 @1600-2400, 6.8, 38.7

Both for auto trans.

Diesel has lower hp but much more torque and lower down rev range, same sprint time but much better economy. This for me gives the diesel the clear advantage in all important areas - if it's turbocharged, so what ? Of course you lose out on two old fashioned areas of importance to the posers/braggers : a bigger number on the badge and hp. If those drive your decision, then buy the gasser. If real-world driveability, longevity and economy float your boat then the decision is very simple....diesel.

There are those who know, and love, modern diesels and the "flat earthers".

pch101 · January 2007

if it's turbocharged, so what ?

It's not a problem that it's turbocharged. I'm only pointing out that if Mercedes had a turbo gas engine that was comparable to the turbo diesel in the E320, that engine would be smaller than 3.5 liters and more fuel efficient.

Let's try this another way: the turbodiesel is more fuel efficient in part because it is a diesel (higher compression, lower revving). But some of that efficiency also comes from the turbocharger (it allows that diesel engine to be smaller and lighter than it would be otherwise), so if you are comparing the efficiency of gas engines with diesels, you need to also take this into account.

What shocks me is that diesel seems to touted as if it is some religion, when it shouldn't be. Again, I have not once said that diesels were bad, I've simply pointed out that bogus comparisons and faulty analogies aren't an honest way to sell the story. This is Automotive 101 that we're talking about here -- power consumes fuel, and turbos provide fuel economy benefits by allowing the use of smaller engines and using less horsepower overall. That is simply fact, and there is nothing to disagree with.

And Happy New Year to you, too.

ruking1 · January 2007

..."Gasser E350

272hp, 350 Nm torque @2400-4000rpm, 6.9sec 0-62mph, 29.1 mpg for European combined cycle.

Diesel E320

165, 540 @1600-2400, 6.8, 38.7

Both for auto trans. "...

Pretty amazing that the MB diesel version has 35% more torque than the gasser. Of course the gasser has 39% more hp.

So if one doesn't WANT 34%% better fuel mileage, get the gasser. If one does and doesnt mind the 39% less hp and likes the 54% more torque, the diesel is the ticket.

bumpy · January 2007

True enough. Any internal combustion engine has a balance of torque and horsepower to distribute through the rpm range. Sacrifice torque on the low end to add horsepower up high, and vice versa. Horsepower determines the top speed of your vehicle, but torque determines how quickly you can reach that speed.

qbrozen · January 2007

I'm only pointing out that if Mercedes had a turbo gas engine that was comparable to the turbo diesel in the E320, that engine would be smaller than 3.5 liters and more fuel efficient.

Heck, if that's all you were trying to say all this time, we've wasted alot of space. Your obvious point is correct. And if my dog could talk, I'd be a rich man. But neither my dog can talk nor does benz offer a small turbo gasser e-class to compare. So both points are irrelevant.

ruking1 · January 2007

correction to #487

Pretty amazing that the MB diesel version has 54% more torque than the gasser. Of course the diesel has 39% les hp.

So if one doesn't WANT 33%% better fuel mileage, get the gasser. If one does and doesnt mind the 39% less hp and likes the 54% more torque, the diesel is the ticket.

pch101 · January 2007

But neither my dog can talk nor does benz offer a small turbo gasser e-class to compare. So both points are irrelevant.

I can't comment on either your dog or Mercedes' specific business decisions as to what it carries in its US lineup, I am simply commenting on how the benefits of the technology should be quantified. And you don't get 38% fuel savings when comparing like products, you only achieve numbers like that when achieving products that differ in more ways aside from the fuel that they use.

ruking1 · January 2007

I would also agree. It is extremely hard for pch101 to make the transition from an obvious long ago acknowledge point(his), to the more than obvious, they dont make equal equal engines or equal equal comparisons.They are so hard to find that he had to pull out a Jetta vs Geo Metro comparison for fuel mileage. Most of the discussion is at the reality of the equally obvious, TRADE OFFS; one being better fuel mileage in a model line up like VW Jetta or MB E320 class. But he has also made it equally clear his Don Quixote quest is to vilify folks with diesel as "NOBODY but HE understands".

Math challenged is one indicator. The one reason math is posted is so folks can punch their own calculators or bring their own #2 pencils and paper and see what the answers are, be it 54% 45% 37% 35% 25% 20%, etc. He has REFUSED to do a the 49-31=18/49= .3673469 %. Ignore it, it CANT be true!!! I think it infuriates him to know that the 2003 VW Jetta gassers 1.8T and 2.0 NON T, at 31 mpg uses app 58% more fuel than VW TDI diesel at 49. EPA highway!! StUCK is a good one word description. Speaks volumes. Let's all but he, move on!!

hypnosis44 · January 2007

"...power consumes fuel, and turbos provide fuel economy benefits by allowing the use of smaller engines and using less horsepower overall. That is simply fact, and there is nothing to disagree with."

I have been unable to verify anywhere that the above statement is accurate and in fact find the opposite to be true. Additionally, the statement turbos "using less horsepower overall" is a non sequiter; did you mean something else?

For about 20 years volvo had both a turbo and non turbo version of the same gas engine in their cars. In every case and in every year power increased and fuel economy decreased with the turbo option compared to the non turbo.

pch101 · January 2007

The EPA indicates that forced induction can improve fuel economy by 7.5%.

Turbocharging & Supercharging

Turbochargers and superchargers are fans that force compressed air into an engine's cylinders. A turbocharger fan is powered by exhaust from the engine, while a supercharger fan is powered by the engine itself.

Both technologies allow more compressed air and fuel to be injected into the cylinders, generating extra power from each explosion. A turbocharged or supercharged engine produces more power than the same engine without the charging, allowing manufacturers to user smaller engines without sacrificing performance.

I hope that this finally clarifies, once and for all, what should be a pretty obvious point!

EPA: "Engine Technologies"

ruking1 · January 2007

For me the turbo (TDI) is useful at altitude and on long long upgrades. Turbos, as most folks know is one of least bullet proof portions of the Turbo diesel and turbo gasser for that matter. Indeed the turbo gasser generates more heat, thus making it more prone to failure than a turbo on a diesel. So if one gets the turbo, one SHOULD drive with those (turbo performance parameters) allowances in mind. Once yone knows what the behaviors are; it is easy and becomes second nature.

I think he has it wrong just as he had it wrong for VW TDI chip issue. He is just doing another fact "less" vilification.

I would also agree. Unless he can cite what diesel models currently have superchargers, half of this so called "proof" point is totally irrelevant on this DIESEL thread.

ruking1 · January 2007

Nah, you are prone to repeating the obvious over and over again. So would you repeat that?

hypnosis44 · January 2007

"I hope that this finally clarifies, once and for all, what should be a pretty obvious point!"

You did not address your statement, or the nonsequiter in the previous post and now are making a different statement. Additionally, do you have a source for the claim of increased fuel economy using "forced induction".

I spent many years in the automotive field both building and racing and no fuel economy improvement was ever seen in any application of a blower or turbo.

pch101 · January 2007

Additionally, do you have a source for the claim of increased fuel economy using "forced induction".

Er, there's a link in the post! Go ahead and click on it, it won't bite.

I've been pointing out throughout this thread what the EPA said -- using a turbo allows you to use a smaller engine to get the same power. In normal street driving, where peak power is not often required, the smaller turbo motor gets to function like a smaller, naturally aspirated engine most of the time, which will make it more fuel efficient.

If you drive at 10/10ths constantly, as you do in racing, you won't get much if any fuel savings because boost is almost always on, and because both power production and energy consumption are being maxed out. But in typical street driving, this is not the case, and the turbo should create some fuel savings as compared to a larger engine with the same output, as the EPA will tell you.

goodcrd · January 2007

"I've been pointing out throughout this thread what the EPA said -- using a turbo allows you to use a smaller engine to get the same power. In normal street driving, where peak power is not often required, the smaller turbo motor gets to function like a smaller, naturally aspirated engine most of the time, which will make it more fuel efficient."

And this is exactly why diesels don't need as much "peak" hp as a gasser of the same size. Diesels produce about 25 to 40 percent more hp at low rpms then gassers of the same size with or without turbos. You still won't admit diesels are the better everyday common joe's performer for commuting. DON'T BUY A DIESEL and let us talk about diesels. This is a Diesel Thread, RIGHT??

Is This the "Day of the Diesel?"

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