cheap fuels

Yep!

2.8 common rail merc unit...

Yes but with no power.

Not "strong" but a damned site better than a smaller asmatic deisel off boost!!!

The TiD's usable power band (i.e.

And from idle (700) to 2000 bugger all... And it runs out at 4200... You have only 2200 rpms that are any use.

No its not. Its physics. The problem is that deisels make no power without a turbo. They boost at about 2k and run out of steam by the slow combustion speed earlyer. No matter how you word it you can never get over these facts.

There are many petrol engines that idle and pull from 800 rpm and rev well into double figures. And they dont need a turbo to do it.

Reply to
Burgerman
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My brothers E280 CDi has the seven speed auto box. It's the V6 3.0 diesel jobby. Goes like stink if you keep your foot in though. Feels /ver-r-r-r-r-r-y/ laggy compared to the Golfs power delivery, but when it's on boost it goes well for a diesel.

Reply to
Pete M

Exactly what's outside at the moment - 56 plate E280Cdi (loan car) - it only feels laggy if you stick the gearbox in comfort mode - in sport it rarely drops below 1500 but it changes down a bit to early for comfort.

Had a CLS320cdi for the first ten days after the accident - that was just amazing - but the temptation to nail it everywhere precluded 30mpg on most runs - awesome though, seemed to come on boost quicker (I think the 280 is tuned for a more petrol-like response with the power further up the rev range) and would activate the traction control for ages...

Reply to
Tim S Kemp

It's not nearly as bad as that - mine comes on boost at 1400rpm, torque

*peaks* at 2000rpm and starts to tail off at 4500rpm. It's not the NUMBER of rpm, it's the ratio of highest to lowest. 3.2:1 means that at any given time I have a choice of 3 gears in which it will pull usefully, and that's with a normal 5-speed box (6-speed diesels exist purely for fashion and marketing reasons), so it's plenty flexible.

I'd much rather have a petrol than a diesel with the same torque, but I'd rather have a diesel than a petrol with the same peak power!

Reply to
Albert T Cone

The ONLY thing Diesels do better than petrol is MPG. No matter how many times you claim otherwise. But for that reason alone they make sense in trucks or in my case an MPV thats 2 tons in weight.

But this only applies if we are talking about fuels at normal roadside prices. Once you look at gas conversions for the petrols (37p up the road, or 22p per litre in a tank in my garden) that advantage is gone. Whats left is a quieter smoother nicer more civilised less harsh drive you get from a smooth 6 cylinder petrol engine. And £1.10 to £1.65 per gallon!

Now I know you can run kero (unlikely to be damaging if a trace of oil is added), or cooking oil (sounds even worse warmed up than a normal rattler does cold!) but by then the economy difference is pretty irrelivant! Both are so cheap to run as doesent matter. But unfortunately all the diesel disadvantages like faster engine wear, oil getting black with soot faster, harsh noisy motors, heavier starting systems, shorter rev range, worse cold starting, smelly deisel fill areas, oily hands from the pump or having to use gloves, less reliability due to a multitude of turbos and control pipes and systems, all still remain. As does the less flexible drivability and tiring drone and harsh engine braking. And you smell it every time it starts up and every time you get out.

You may have worked out by now that I am not keen.

Reply to
Burgerman

Nonsense.

Nonsense.

And something that needs revving to perform.

No, we're merely ascertained that you have a chip in your shoulder.

It's okay. Just admit that you don't like it, rather than inventing stuff to claim that they're somehow inadequate.

Reply to
DervMan

[snip]

Eh? No.

No it isn't. It's comparable. No different.

Nope.

Peak torque is 1,900 - 2,500 rpm. It moves from 91 bhp at 2,500 rpm to 115 bhp at 4,300 rpm but doesn't suffer from the rapid drop off in torque until ~4,800 rpm.

There's a relatively big lump of torque from 2,000 rpm upwards until the far side of the rev line.

My Accord needed to be in the higher lift engine speed to come close to matching the (lower maximum power) Saab. It needs second at 45 to exceed the Saab's acceleration as the Saab in fourth. Is the Accord quicker? Driven 100% yeah I'd say it is. Neither is easier to drive at 100% either, both have well set up gearing.

Driven less than 100% the Accord needs more changes to maintain decent acceleration relative to what it can do. The TiD doesn't.

That isn't true.

They come on boost earlier in the rev range. ~1,400 rpm.

No matter how you protest about a narrow rev band, this fact is irrelevant with the right gearing and a driver able and willing to change gear.

Or an automatic transmission.

And yet so few are used in minivans and family cars.

Reply to
DervMan

Sorry but its NOT nonsense. They do everything else WORSE.

Now you are saying that they dont make sense in heavy big vehicles? You lost me...

Wrong. They dont "need" reving to perform It is easy to make a petrol engine make MORE torque at low rpms than a deseasel just by fitting a tiny turbo like a desel needs to have since it couldnt pull the skin off a rice pudding without one. But since a petrol engine can already do pretty well at idle onwards without a turbo and can rev higher too it makes more sense to use that to your advantage and fit a bigger turbo that can work at higher rpms giving much more power than any deseasel turbo of the same size. And revs go through a gearbox which is also called a torque multiplier. BHP is a meaningful measure. Torque along tells you absolutely nothing useful unless you know the rate at which it can be produced. And then its called power which CAN be directly compared.

Not "we" but you - who appears not to like facts and physics - have "ascertained" that. Incorrectly. I work on facts.

I dont like it. And I dont like it precicely BECAUSE of all the "stuff" which happens to be perfectly true and not invented!

They are in comparison to an equivelent petrol engine. The ONLY thing they do better as I said at the start of this (in the cheap fuels thread) is save fuel costs.

Reply to
Burgerman

Diesels have nothing of any use after peak power on the graph. Most petrol engines can have considerable overev capability. Diesels have a fuel burn speed issue.

A whole 4800!!!

But that hole that all diesels have from idle to 2000 is horribly useless. Traffic lights... Floor it, nothng nothing woosh nothing... Change gear - same again, repeat about 75 times due to the short rpm useful band...

Different cars/setups/styles all pretty meaningless.

Then the accords crap.

Ok they make so little its rediculous. Thats why you will find it very hard to find a modern car with a diesel and no turbo. And if you do its slow.

If they do then they run out earlier as well. Unless you go for massively complicated triple turbo V6 etc with its unreliability problems thats in my brothers 3 litre diesesel merc. And it still isnt as smooth or as flexible as my vr6 van!

Yes well not everyone wants to spend all day fighting a clutch pedal and gear stick just to keep rowing the thing along.

The reason that they are only now making diesel autos (many years after they started doing auto petrols in the 40s) is because technology and complication and microchips as well as 6 speed autoboxes have become common. In the days of two, and three speed autoboxes the diesel just was not flexible enough to cope. Now with enough gears they are - just. But it certainly does not make them nice to drive. As my bros merc testifies. And it spends most of its time having issues diagnosed...

All the ones are more flexible than any turbo diesel. Would you like to look at a few torque curves because I have thousands in my database fron various customers using my dyno software all over the world. In all cases the widest and flatest torque curves are from petrols and the shortest and the most exagerated are from turbo diesels.

Reply to
Burgerman

The Windstar is no more, replaced by the Freestar........ Fitted with a 4.2L OHV V6, 201HP @4250 rpm, 263 ft/lbs. @ 3650 rpm. C/W 4-spd auto. World of Wheels comment, "Gruff, noisy low-tech engine".

Dodge, you know it makes sense...:-)

David C

Reply to
DavidC

Big snip.

Got to disagree young Sir.

I own a US (built) V6, a 2.5 litre Cleveland Duratec, fitted in an '04 Mondeo with the 6-speed manual, & I find it to be seriously flexible.

It's never necessary to use all 6 ratios on the public highway, & it's quite possible (albeit pointless) to start in 1st & shift straight into 6th! The usable rpm-range is from app. 850 to 6,200, far better than any diesel.

I've had a 3-day loan (from Ford's) of a diesel Mondeo, with the same

6-speed box, (but with a taller final drive & wide internal ratios) & found it to be more economical, but a PITA to drive. Not possible to shift beyond 4th in town, 5th on our local 50 limit main roads, but it would (just) accept 6th at 60 mph.

Even as a poor early retiree I'll glady fork-out the extra pennies for quite, smooth & lazy driving from my little V6.

As for US cars, I've driven quite a few V6's on vacation from '94 to '06 & the only lump that felt gutless was the Mitsubushi 2.5L in a Chrysler Sirrius. Other "full-size" Chryslers, including a 2.7L Intrepid ES, 2 LHS's & a

300m, all with the 3.5L SOHC, 24V lump have been flexible & economical, & plenty quick enough to upset plod!

A Buick Le Sabre with a 3.8 litre OHV was not too slow in a straight line, but not so clever elsewhere. (But I'm not old ehough to drive a Buick, & I never will be-:)

Last year I took an '06 Chevy Impala out of Toronto, with the base 3.5 OHV, 12V but VVT. Dropped down to Philly, back-up to Montreal & then T'O, at a 30 mpg (UK) average. Due to a having a 4-speed suto with a seriously high top (30+ mph per 1Krpm) it would often drop back to 3rd below 60mph, when passing, but it was a quiet & refined tourer. (And at app $27K CAND, cheap too.)

David C

Reply to
DavidC

A diesel is always quicker than an equivalently powerful petrol, no matter how many times you refuse to acknowledge it :)

I'm not under any illusions about diesel being a superior engine type, or having a better power delivery or anything like that, but given a budget for running a car, which *everyone* has, then a diesel will nearly always be the real-world quickest option. End of story.

Blah blah, imaginary reliability bollocks, blah, "Oh no, my beautiful hands smell all oily!!", blah, imaginary reliability bollocks.

Dude, have you even used a diesel in the last 20 years? There is no smell, the good ones are refined to the point that (when warm) you almost can't tell them from a decent petrol unit and they are *quieter* at a cruise. If anything, mine has insufficient engine braking; it's definitely not too harsh.

Aye, for sure. And good for you, frankly. If I could run something equivalent with a huge/turbo'd petrol lump for the same budget, I'd do it in a flash, but as things are any petrol lump which goes as well costs an extra feckload a year, so it's not an option.

Reply to
Albert T Cone

You know, in this world of people posing as someone completly different online, in order to groom the innocent, I somtimes Wonder if that big macho burley engineer Burgerman isn't the real one at all, but some 17 year old 6th form girl into britney and Justin, and posing as a big gruff bloke with an import bird and tasty carer he likes to get drunk.

After all, would a real dirt monkey who builds dynos and nitrous systems really care about getting dirty, and surely the smell of oil is one of the most manly fragrances going.

Reply to
Elder

Yes it is! But not deseasel oil!

Reply to
Burgerman

Wuss :P

Reply to
Albert T Cone

Castrol R

Reply to
Burgerman

I can't get the missus to wear it as perfume, pity....

Reply to
Tony Bond

Millers XFE-PD. Mmmmm....

Reply to
Albert T Cone

So how come so many people run 'em?

Utter gibberish.

Not much torque x plenty of revs = power.

Lots of torque x fewer revs = power.

See above. 200 bhp from a turbodiesel is the same 200 bhp as from a petrol, turbo or otherwise.

I don't disagree that the best of both worlds is a big capacity, 12 cylinder with at least a couple of turbochargers, but the fact is that the majority of UK specification, UK market cars are available with a range of relatively anemic four or six cylinder engines, petrol and diesel.

When one compares what one can buy for the money, it may be something like a

2.x blah petrol or a 2.x blah turbodiesel.

Bet the turbodiesel has less horses under the bonnet, but it's easier to access all of those horses without using every last rpm.

If diesels have such an appaling narrow power band then:

  • why are there manual diesels?
  • why isn't there a different driving test?
  • why do people cope with them?
  • why do so many people enjoy driving a modern turbodiesel?

Define equivalent?

In power?

In capacity?

In cost?

In torque?

Except you're wrong.

Don't blame your unwillingness or inability to change gear on the car, it's driver education, or lack thereof.

Reply to
DervMan

Dunno where you live or how you work that out. Round here it's 50p/L from Calor in red cylinders.

I live 200 miles north of here - same price

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Refill, Price: £47.25= £1.005/Kg = £0.50p/L(costs more in small sizes you suggest) OK this ones 42.4p/L but I don't live in SA61-SA73 (Haverfordwest - an area that I suspect has a large number of non mains gas users).
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Peter Hill Spamtrap reply domain as per NNTP-Posting-Host in header Can of worms - what every fisherman wants. Can of worms - what every PC owner gets!

Reply to
Peter Hill

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