RE: Diesel myths debunked

[infradig]

StottyZr said:

blueg33 said:

I wonder.......

A roads with traffic, 200bhp diesel vs 200bhp petrol which would get your overtakes done fastest and hence get you ahead of more of the slow moving cars.

I am pretty certain that from my experience (with auto's) it would be the diesel. In the diesel at 40mph starting your overtake, you will already be at or around max power, in the petrol you will not get to max power before you are well over the speed limit unless you trundle around in traffic in 3rd.

Both with 200hp, would be about the same floor both auto's and they would drop to the correct gear and both produce a very similar amount of hp.

This reminds me of a situation a couple of weeks ago,whilst following my brother home in a 944 Turbo he'd just bought. An overtaking opportunity presented itself and we both went for it past a small queue of 4 or 5 cars. I was in a C220cdi auto and almost pushed the Porsche from 40 to 80,it only started to pull away as we pulled back over and needed to slow down for more traffic. I was a little upset as the C Class is the most boring nasty little photocopier salesman/hire car imaginable and the 944T was once a junior supercar.

[Dave Hedgehog]

loudlashadjuster said:

Dave Hedgehog said:

the V6 bi turbo is 200bhp? i got it down to 16.2mpg on a run in london

Sorry, I missed the fact you said it was a V6 and blindly made the assumption it was a 2.0.

I can understand the MPG now then! I know it's pretty easy to get an E320 CDI into the teens aswell.

the most economical thing i have driven recently was an A5 2.0T (petrol) black edition quatro, 200bhp, mid 6s and i got 31mpg (8 more than i normally get) out of it on a rush hour run using the stop start technology and driving it like a mini cab following the recommended gear display, amazed me. Pretty fun when pushing on as well but very big.

[Froomee]

k15tox said:

Diesels can be quick.

Maybe they will use a 335d and 640d mapped in the new film

[blueg33]

Dave Hedgehog said:

the V6 bi turbo is 200bhp? i got it down to 16.2mpg on a run in london

In the 2012 models Its a single turbo that gives 242bhp (I believe) the bi turbo gives more 309bhp (bi turbo was not avaliable until end of 2011)

If you were driving the single turbo version I have no idea how you got average mpg that low. Its never been that low in mine. The lowest average in mine is circa 23 mpg for the first 12 miles on a cold winter morning with all the electrics on, after the first few miles its up above 30mpg

[BBL-Sean]

Devil2575 said:

Motorrad said:

Take a car like a Golf GTi- a lower spec diesel engined Golf costs basically the same, being very generous there's a 15mpg difference in it overall. Like the UK diesel costs more but unlike the UK the cost of fuel is still relatively low. You're talking a saving of a few hundred dollars a year for a far less atrractive vehicle plus your average American isn't going to want to be bothered to hunt around looking for a place that sells diesel. They just want to drive in, tank up and fk off to Jack in the box.

Legislation is the only thing that will drive them into diesel vehicles.

New Golf GTI TSi 3dr with leather list price = £25330 Combined economy figure 38 mpg
New Golf 2.0 TDi 140bhp GT with leather list price = £21830 combined economy 58 mpg.

The Golf GT looks very similar to a GTI and cost a good £3.5k less. That's a nice holiday or a good few more options ticked.

No idea how those prices would change in the US but lets look at the potential savings.
The Golf GT looks very similar to a GTI and cost a good £3.5k less. That's a nice holiday or a good few more options ticked.

Average annual milage in the US is 13476 miles

http://www.fhwa.dot.gov/ohim/onh00/bar8.htm

Cost per gallon of diesel $4 (based on previous link I posted)
Cost per litre of premium petrol (which i suspect is what a GTI should be run on)

But for the sake of argument we'll go for regular which was $3.71 a gallon.

Recalculate this to UK gallons and you get:

Diesel = $4.80 per Uk gallon
Regular = $4.45 per UK gallon (based on 1 US gallon = 0.833 UK gallons)

So cost per year based on average milage = $1577.97 Petrol and 1115.23 Diesel

So $463 Dollars.

Ok so not a massive saving but when you look at the average miles covered by male drivers in the 20-54 age range this is up at about 18k a year so the savings will get bigger. $618 for an 18k annual milage, based on regular gas. Buy premium for your GTI and that saving becomes $784.

The other thing to consider is that the Golf is a relatively economuical can compared to many US cars. Imagine the difference between a V8/V6 with an auto box and a 2.0 TDCI. It would easily be over $1000 a year.

I think all that needs to change is fuel prices keep rising in the US and eventually it will happen. Either that or a few people start to try a modern TDCI and realise that for most drivers they are fine. Not for die hard petrol heads granted, but most people aren't.

As for complexity, how would most non petrol heads know that the car was complex? Besides, a lot of petrol engines are getting very complicated now as well.

In the U.S., the Golf GTI is not available with a diesel, but the base model Golf is:
2.5L 170 hp petrol, MT, 2-door w/no package options -- $17,995 US base price; 23/33 mpg (in U.S. gallons; combined mpg figure is not shown on the web page)
2.5L 170-hp petrol, MT, 2-door w/all package options -- $20,655 US base price; 23/33

2.0L 140-hp TDI, MT, 2-door w/no package options -- $24,235 US base price; 30/42 -- +$6,240 over petrol, with 7/9 mpg improvement (city/hwy)
2.0L 140-hp TDI, MT, 2-door w/all package options -- $27,640 US base price; 30/42 -- +$6,985 over petrol, with 7/9 mpg improvement

SOURCE: http://www.vw.com/en/models.html

So in the U.S., the diesel costs significantly more than the petrol version, has 30 less hp, and the published mileage differences are minimal. Coupled with the higher cost of diesel fuel - which was half the price of regular unleaded thirty years ago, but is now typically as much as or slightly more than premium unleaded - it is indeed a "no-brainer" for consumers in the U.S.

edit -- added hp figures

Edited by BBL-Sean on Friday 27th April 16:58

[Vladimir]

The 335d is also well down on power and needs urea (!!) added to make it work in the States.

US diesel is a lower grade than Euro stuff.

[tomoleeds]

if our goverment was not so greedy,i would prefer a petrol car,my a4 diesel averages 50mpg but parts are expensive, egr valves, injectors,pumps, DPF, plus noisy on idle. if we paid a sensible amount in vat on fuel we should be paying 70p a litre. not £1.40,add on road tax,(forever going up)we are the getting ripped off

[Paul_M3]

Dave Hedgehog said:

im not bothered about the economy, only been getting 18mpg out of the S3, its the engine dynamics of the oil burner i find very unpalatable, i would rather have the s3 (a 7.5/10 car) than a passat oil burner and a 911 GT3 RS for summer weekend hooning because after a week in the passat i would want to crash it to inject some character into it

give me an RS4 as a daily drive and ill happily take the GT3 for play time

Really? Honestly?

I swapped my modified e46 M3 for a 320d Auto and an Elise SC.

I think it's the best car decision I've ever made.
No matter how good the M3 was, my 25 mile journey to work was still completely dull 95% of the time.

Now it's still dull, but MUCH more relaxing as the 320d auto is such an easy, lazy car to drive.

[Devil2575]

StottyZr said:

Dave Hedgehog said:

Devil2575 said:

I had this when I first drove a Diesel, an 07 VW Passat. I couldn't work out why it got rubbish economy. They I started to alter the way I drove it and it...

By the end of a 400 mile round trip i'd improved the mpg on the trip computer from 35 to 55 mpg.

Boring yes but in a boring car sitting on the motorway a petrol engine is not really any more exciting, IMHO.

but thats the thing i dont want to change, honestly i would rather take the train than drive like miss daisy

I don't think hes talking about driving slowly. I think he's getting at people driving diesels at 2200rpm when it would be more than happy at 1400 and 2gears above. You can drive quickly whilst being efficient.

Yes. You don't drive a diesel like a petrol. Trying to results in you not going that quickly but using a lot of fuel.
Keep the revs between about 1500 and 3500 rpm and they go realy well and get decent economy.

[aycee]

If its an everyday car,an Auto or a Luxo barge, Its got to be TD for me.
E320cdi-
You wouldnt know its diesel,
Never broken in 90k miles,
It will cruise at speeds that will get you properly locked up,not just banned.
It accelerates as quick as, and maybe quicker than, any equivalent 3.0 petrol Auto comfortably.
It does a million MPG if you want to . I managed 62mpg when I tried on an anorak once.
In this day and age and with UK roads as they are, You WILL NOT get anywhere quicker in a Petrol.
The only place you would see a differance would be on a track or a deserted very early Sunday morning Hoon.

That said, There is one thing a petrol is better for, ....the adrenaline buzz gained from 500hp + on a weekend.Diesel just wont cut it then.

[cossey]

The EU has in the last couple of weeks released the results of its "Real Driving Emissions" where they put portable emissions measurement systems into cars and drove them on real roads and it shows that for the latest Euro 5 diesels (ie the ones you buy now) the cars tested were 4-7x higher in NOx output than the legislation and in reality were almost no better than 10 years ago.

this is part of a major consultation that they are running with the draft proposals (due to be confirmed next month) that the cycle will be changed to something more representative (WLTC instead of NEDC) and that there should be extra real world tests with the limits being similar to the USA "not To Exceed" limits of 25% IE if the emissions are at any point in time over 25% more than the legal limit the car fails and must be withdrawn from sale.

Several petrol cars were tested and found to be generally passing the limits.

The car manufacturers are expecting the draft to be passed and are frantically rewriting their plans for Euro 6 when the new rules are likely to come into effect. this will mean a huge increase in emissions related systems on diesel (including small cars) which is not going to have a good impact on purchase costs, maintenance costs and fuel consumption

[Devil2575]

BBL-Sean said:

In the U.S., the Golf GTI is not available with a diesel, but the base model Golf is:
2.5L 170 hp petrol, MT, 2-door w/no package options -- $17,995 US base price; 23/33 mpg (in U.S. gallons; combined mpg figure is not shown on the web page)
2.5L 170-hp petrol, MT, 2-door w/all package options -- $20,655 US base price; 23/33

2.0L 140-hp TDI, MT, 2-door w/no package options -- $24,235 US base price; 30/42 -- +$6,240 over petrol, with 7/9 mpg improvement (city/hwy)
2.0L 140-hp TDI, MT, 2-door w/all package options -- $27,640 US base price; 30/42 -- +$6,985 over petrol, with 7/9 mpg improvement

SOURCE: http://www.vw.com/en/models.html

So in the U.S., the diesel costs significantly more than the petrol version, has 30 less hp, and the published mileage differences are minimal. Coupled with the higher cost of diesel fuel - which was half the price of regular unleaded thirty years ago, but is now typically as much as or slightly more than premium unleaded - it is indeed a "no-brainer" for consumers in the U.S.

I'm interested as to why in the US the diesel gets such poor economy? A 2.5l petrol only gets 7/9 mpg worse than a 2 litre diesel?

Maybe there's something else going on here?
On paper the US 2.5 gets worse than the EURO GTI, which isn't supprising. What is supprising is that the US Diesel model gets a lot worse mpg than the Euro diesel. Combined of 58 for the Euro model but in the US thats 30-42 US which is 36-50mpg UK? So a combined which will be around 42mpg?

Doesn't make a lot of sense.

According to the US VW site they only list the 2.5 as an engine option, no diesel.

http://www.vw.com/en/models/golf/trims-specs.html#...

Call me suspicious about the US EPA estimated milages but IIRC these were the ones that stated the latest BMW M3 did about 10 mpg and the Boss Mustang did 25 mpg...

Edited by Devil2575 on Friday 27th April 17:30

[Hellbound]

angusc43 said:

frosted said:

sealtt said:

I live in central London & work in the city - i drive in to work - this is about 3.0 miles and most of that journey - which can be 20mins-40mins - is spent sitting in congestion. However, I am sitting in a SL with big 5.5l supercharged V8... so every time i pull away i get to hear that great noise and i can still occasionally enjoy gunning it through a tunnel or empty street.

I am only doing about 40 miles per week and so 5mpg or 20mpg doesn't really make any material difference in cash terms. However, I spend a decent amount of actual time in the car each week and a big V8 is massively superior & more enjoyable than just about any diesel I can think of.

So for me, living in a major & congested city makes buying a big engine gas guzzler a no brainer - only if you are doing big mileage on motorways is a diesel worth it.

If you had to cross London twice a day I bet you wouldn't be driving a supercharged v8 .

I did it on Wednesday in a n/a 5.0 V8 and it was fine, thanks. In fact I've been criss crossing London since 2003 in either a 4.3 or a 5.0 V8. Not once in those nine years have I had the urge to buy a diesel. One of the joys of living in London in low mileages. Low mileages = petrol V8's all day long. Or in my case nearly all decade long.

Thanks for illustrating exactly what's wrong with London; Short to medium journeys made in high polluting vehicles in high density traffic by people who are utterly oblivious to the needs of the majority of inhabitants around them. Respiratory disease and respiratory failure are the biggest killers in cities like London. This is why the next mayor needs to really start doing something about cleaning up London's air, both with buses/taxis and private/business vehicles.

I liken it to being stuck in a lift with 10 people, one of whom thinks its perfectly fine to start puffing on a cigar. Sure you'll ignore it the first couple of times. But after a month of breathing in that poison, you're going to want to slap the thing off his face. Although he'd probably suggest you took the stairs or found another place to work. It's sad we still live in an era where such bizarre logic is still supported by an alarmingly large number of people.

[gumsie]

Devil2575 said:

EDLT said:

Those myths aren't debunked, diesels are louder, dirtier and rougher than petrol engines.

Depends on how you look at it.

................However in absolute terms a decent modern diesel engine is relatively smooth, quiet and not at all dirty. Those 'Myths' are certainly no longer a reason not to buy a diesel for the bulk of the non petrolhead public.

Did you see what you did there?
As for reasons not too, long before I was a petrol head, (and back when diesels were well clattery admittedly), I heard one and decided I NEVER wanted my car to sound like that. Petrol engines weren't hugely smooth back then either.

[Devil2575]

gumsie said:

Did you see what you did there?
As for reasons not too, long before I was a petrol head, (and back when diesels were well clattery admittedly), I heard one and decided I NEVER wanted my car to sound like that. Petrol engines weren't hugely smooth back then either.

I don't get your point. Back in 1990 I saw a PC game and though it wasn't worth the money. That has no refelction on how good they are now.

Relative to contemporary petrol engines diesels are now a lot smoother. Smooth enough for it not be an issue for most of the non petrol head public.

[blueg33]

If its any help to the discussion, electric motors are even smoother than petrol engines, and run at high revs.

Shouldn't everyone be demanding that we go to those? They offer everything and more that the diesel haters say is good about petrol.

[otolith]

Hellbound said:

Thanks for illustrating exactly what's wrong with London; Short to medium journeys made in high polluting vehicles in high density traffic by people who are utterly oblivious to the needs of the majority of inhabitants around them. Respiratory disease and respiratory failure are the biggest killers in cities like London. This is why the next mayor needs to really start doing something about cleaning up London's air, both with buses/taxis and private/business vehicles.

To be honest, I shouldn't think a large capacity Euro3 petrol is particularly polluting in terms of the pollutants which cause human respiratory health issues.

[Patrick Bateman]

StottyZr said:

blueg33 said:

I wonder.......

A roads with traffic, 200bhp diesel vs 200bhp petrol which would get your overtakes done fastest and hence get you ahead of more of the slow moving cars.

I am pretty certain that from my experience (with auto's) it would be the diesel. In the diesel at 40mph starting your overtake, you will already be at or around max power, in the petrol you will not get to max power before you are well over the speed limit unless you trundle around in traffic in 3rd.

Both with 200hp, would be about the same floor both auto's and they would drop to the correct gear and both produce a very similar amount of hp.

Yes but if you know how to use a gearbox it doesn't mean anything with regards to the original comment.

Diesels are fine for lazier overtakes but lets not pretend that means they're going to be faster than a petrol equivalent just because someone can't anticipate an overtake early.

[Vladimir]

Patrick Bateman said:

Yes but if you know how to use a gearbox it doesn't mean anything with regards to the original comment.

Diesels are fine for lazier overtakes but lets not pretend that means they're going to be faster than a petrol equivalent just because someone can't anticipate an overtake early.

You overtake lazily? Maybe learn to drive?

[angusc43]

Hellbound said:

angusc43 said:

frosted said:

sealtt said:

I live in central London & work in the city - i drive in to work - this is about 3.0 miles and most of that journey - which can be 20mins-40mins - is spent sitting in congestion. However, I am sitting in a SL with big 5.5l supercharged V8... so every time i pull away i get to hear that great noise and i can still occasionally enjoy gunning it through a tunnel or empty street.

I am only doing about 40 miles per week and so 5mpg or 20mpg doesn't really make any material difference in cash terms. However, I spend a decent amount of actual time in the car each week and a big V8 is massively superior & more enjoyable than just about any diesel I can think of.

So for me, living in a major & congested city makes buying a big engine gas guzzler a no brainer - only if you are doing big mileage on motorways is a diesel worth it.

If you had to cross London twice a day I bet you wouldn't be driving a supercharged v8 .

I did it on Wednesday in a n/a 5.0 V8 and it was fine, thanks. In fact I've been criss crossing London since 2003 in either a 4.3 or a 5.0 V8. Not once in those nine years have I had the urge to buy a diesel. One of the joys of living in London in low mileages. Low mileages = petrol V8's all day long. Or in my case nearly all decade long.

Thanks for illustrating exactly what's wrong with London; Short to medium journeys made in high polluting vehicles in high density traffic by people who are utterly oblivious to the needs of the majority of inhabitants around them. Respiratory disease and respiratory failure are the biggest killers in cities like London. This is why the next mayor needs to really start doing something about cleaning up London's air, both with buses/taxis and private/business vehicles.

I liken it to being stuck in a lift with 10 people, one of whom thinks its perfectly fine to start puffing on a cigar. Sure you'll ignore it the first couple of times. But after a month of breathing in that poison, you're going to want to slap the thing off his face. Although he'd probably suggest you took the stairs or found another place to work. It's sad we still live in an era where such bizarre logic is still supported by an alarmingly large number of people.

Well I suppose I should have put some context behind my statement. I like living in London as I can cycle or walk, use a tube or a bus or use the overground services that proliferate. The car is primaraily for longer trips out of town.

I think I have actually driven to work three times this year. Twice because I'd done my back in and once because of appalling rain. The rest of the time I cycle there and back.

I was just responding to the somewhat odd comment from the other poster that if someone had to cross London by car they'd choose a diesel. I most certainly wouldn't!!

If, however, my wife ever managed to persuade me to move out of London I'd probably have to buy a diesel as everyone seems to drive everywhere once you're out of the capital.

I would, however, have an SL55 or an S4 Cab tucked away for fun. This is PH, not What Car :-)