S.A.F.E.D

[CreepingJesus]

Crikey...I think we're going to have to agree to disagree here, Will. Altho' I will take issue with your quote. You've selectively edited what I said:

I wasn't sure about this at all, as in fairness, it seems counter intuitive. But then I've done a number of bloody SAFED courses, and often turns out to be the case, that counter-intuitive is correct.

In fairness, it may seem overstated a little, but that's only without understanding the context of my professional driving career. Hauling 44 tons of shit around the land for pennies, creates some curious situations in respect of driving for economy, and that's what we, as professional drivers are being taught over and over again. Think about, analyze, question. If it works, it works. Go with it. The boss will like paying less for diesel, and all the fluffy little animals will form a chorus of praise. Or something.

You're relying on theory to provide absolute answers, and as a man of science you should understand that theory is rarely the same as real life. Especially in a system as complicated, and at the mercy of hundreds of external factors, as the humble internal combustion engine. Whether it's Otto cycle or Rudy Diesel's Manky Marvel.

For example...when I was studying mechanical engineering way back when, I was fortunate enough to be in favour with a senior lecturer who had some great contacts in automotive R+D. To further my studies, he leant me some documents, for my eyes only to see what I could learn. They were from PSA and Bosch, and were the genesis of the HDi engine we know today. They computer modelled and theoreticised to the nth degree, but when they put the embryonic high pressure system on a humble XUD, the results were awful.

A rudimentary 4v-per-cylinder head helped, but didn't solve the problems. They quickly accepted that either a) a radical redesign of the XUD's combustion chamber, or more likely a whole new engine was needed to counteract the problems.

The moral of the tale? Theory is all good and well (indeed it's where we start from), but until you put it to the test you can never truly know. The same is as true of me trying to get to my next pie and Bru without getting an order of merit from OPEC, as it is about a multi-million franc/deutschmark research project.

Disbelieve me all you like; I have evidence. Which, in science is the 'possession is 9/10ths of the law' moment. Fuelly is only numbers, and while not infallible, you'll have to trust that the numbers I put in it are good enough. It's just a calculator for those of us who can't file receipts in a usable format. My fleece pocket's even less reliable than I am.

What I don't have is a 'why'. If I had a ream of data minutiae like the PSA/Bosch team had, I might be able to reverse engineer the thing to a conclusion, but I don't, so I can't. It's real, and it exists - not only for me in the V70, but the same appeared to be true of the 2.0 8v Passats I had...

Lordy, another MegaPost from me...just what the world needed.

[worldofceri]

Glad I'm not the only former mechanical engineering student that now drives lorries for a living. Although you seem to have actually learnt something from your studies, Mr Jesus, unlike me.

 

Anyway, it's interesting how many of us seem to be justifying our use of high speeds with impressive economy figures. My self included!

 

In fact, Fuelly congratulated me yesterday for acheiving my best evah economy of 35.1mpg. That was on a run from Coventry to Edinburgh, four blokes up and 80-90mph most of the way. Dunno if it would have been even better had we bimbled up at 65.

[gtd2000]

I used to achieve 47.5MPG in my old Hyundai Coupe on a run from Newport (Wales) to Galashiels sitting at 70~80MPH, which is pretty impressive in my estimation.

 

 

And that was on those dastardly Chinese Sunfils

[willswitchengage]

^ Oops sorry about misquote, just snapped out a generic line from your paragraph - nothing else intended! Maybe we should pose this to Yahoo Answers to let the REAL experts (pistonheads I've discovered in the past has similar levels of intelligence in its demographic) decide...

[messerschmitt owner]

^ Oops sorry about misquote, just snapped out a generic line from your paragraph - nothing else intended! Maybe we should pose this to Yahoo Answers to let the REAL experts (pistonheads I've discovered in the past has similar levels of intelligence in its demographic) decide...

real life fuel consumption is nothing like the theory, hence why real life consumption varies so much in comparison to EU tests on current cars.

 

I can get from 24mpg to 75mpg on a run on my smart roadster, depending on the weather, how I drive and at what speed.

 

I can tell you that at 120mph, my tuned smart roadster gets 22mpg on an autobahn (the one between Bremerhaven and Dortmund), that I can get 75mpg on the motorway when paying careful attention to the real time fuel consumption, varying speed to suit best fuel efficiency. I can get 220miles out of a tank of my best at almost 450 miles (from 31 litres), which involved proper hypermiling and slipstreaming on a dual carriageway on the commute to work, as well as using no more than 40% throttle input.

 

stuck 10ft off the rear of a truck involves were little fuel consumption and a steady speed.

 

I believe WTC's 47mpg as it is achievable if driving like you have egg shells on the pedal.

[willswitchengage]

^ exactly there you go, but the EU test thing is "real life" in that is actually measures hows much how much fuel goes into the engine over the prescribed cycle as opposed to a theoretical estimate, that only differs from real life in that in "real life" people tend to believe the two right hand pedals are on-off switches when travelling between traffic lights. It's the efficiency paradox that if you buy a 70mpg car, you'll use it more and drive more "enthusiastically" than you would on your old Volvo 740, and spend net more on fuel in the process. And then write to Which? to complain.

[CreepingJesus]

Glad I'm not the only former mechanical engineering student that now drives lorries for a living. Although you seem to have actually learnt something from your studies, Mr Jesus, unlike me.

 

So it isn't just me! Well, me and a couple of other guys I know...! I certainly give off the impression of having learnt stuff, but I'm easily outwitted by the dog, so it isn't true. Just don't tell anyone .

 

...exactly there you go, but the EU test thing is "real life" in that is actually measures hows much how much fuel goes into the engine over the prescribed cycle as opposed to a theoretical estimate, that only differs from real life in that in "real life" people tend to believe the two right hand pedals are on-off switches when travelling between traffic lights. It's the efficiency paradox that if you buy a 70mpg car, you'll use it more and drive more "enthusiastically" than you would on your old Volvo 740, and spend net more on fuel in the process. And then write to Which? to complain.

 

...or the motoring section of the Daily Fail.

The problem with standardised testing of fuel economy is the 'standardised' bit. A team of drivers drives the same selected course a number of times each, and the results are averaged out. The 'course' may well be a proving ground closed loop, and the drivers will be split between the host testing body, and the manufacturer of the car being tested. They'll be well above average drivers, and probly know the test course inside out.

Everything will be averaged or 'statistically adjusted' out, to the possible maximum, rendering the official fuel economy figures little more than an outdoor bench test. And I'm sure the manufacturers wouldn't have it any other way. Otherwise, they'd form their own 'testing' organisation, and get the figures they want. '45mpg @90mph' tho', will never feature, 'cos they couldn't be seen to be so socially irresponsible.

So we have to accept the compromise, that the test's flawed, but at least it's a consistent flaw which affects all the test data equally. Again, engineers have to work with compromise, so it's not really a big deal; and the marketing bods get some numbers to wage the sales war with.

Sadly, the figures don't reflect reality for many people - but that's where education and social engineering come in. If you can persuade a few that it's okay to back off, and spread the culture out, then maybe fuel use could be reduced. There's a disconnection in the understanding of how to achieve 70mpg from a car that's advertised as such. Some people do indeed believe that they'll still get 70, while ragging the bloody thing. Some education required...

 

I don't want it to sound like I'm picking on you, I'm just being bloody minded! I can't help seeing what happens to the straight ahead scientific view, when it's subjected to a bit of lateral thinking. I take the Fortean approach to my science and engineering!

[Spiny Norman]

Another point worth making is that most non-car people have no idea how to work out their mpg figures anyway, and base their idea of their car's fuel use on nothing more scientific than how often they visit a petrol station.

A quick poll amongst a few mates a while back revealed the following...

 

Mate A has a Diesel Saab 9-3, and thinks it does mega mpg because it once got him from Glasgow to Dorset on one tankful. (450 miles in a Diseasel with a 15 gallon tank, I might be impressed if it got back to Glasgow again on the one fill up...)

Mate B has a Mazda 2 and thinks it drinks like a fish because he's always filling it up. He does over 15k a year in it and its tank is about 8 gallons....

Mate C has a 1.8 petrol Zafira and thinks it's terrible because he only puts in the same £20 he's always put in the tank at any one time, and wonders why it only takes him 100 miles rather than the 200 it took him in his old Focus. I had to explain that today's £20 worth is about 3 gallons instead of the nearly 5 it was only a few years ago.

 

None of them could actually tell me how many mpg their cars did and only one of them could even begin to come up with an accurate way to measure the figure.

[fiatdaft]

You do know that manufacturers fuel consumption tests are actually done on a rolling road in the equivilent of an automotive labaratory and they are all set up in the same way,thats why on most of the up to date non torque converter autos the manufacturers have the gears programmed to change at certain points so that on paper the mpg and co2 emmisions look better than the manuals,but the reality is very different.

 

Hardly real world .

 

The idea of a bunch of boffins with a can of petrol , a car on a test track with a pencil and paper is a wee bit out of date !

[willswitchengage]

I reckon they all put these on their cars during the tests to boost efficiency

 

http://www.gadgetsnstuff.co.uk/index.as ... id=1623343

 

 

Also LOL at some of ecomodder's hypermiling tips: #97 "honk at pedestrians so they don't walk out infront of you therefore avoiding unnecessary braking"

[Cavcraft]

I see a lot of new trucks are automatics now, apparantly they're better on fuel than manuals. Only if driving tankers they say they're a nightmare because the sloshing round of the liquid confuses the box and it keeps changing gear to whatever it thinks is the right one.

[Largactil]

It's funny - I never even think about it on my modern, but tend to keep a log of what the Peasant Pug manages...

 

(I use the tried and trusted 'Brim it - Record mileage - Drive till near empty - Brim it again, and work out how many litres it took to cover the distance you've just driven).

 

Thing is, speed doesn't seem to make a huge difference to the TU9 / 954cc powerhouse.

 

Two trips from London to Stirling - 420 miles

 

Trip 1 took 7 hours (with x3 piss / hoof burger stops), averaged 60mph and consumed 9.1 gallons of unleaded = 45.6mpg / £54.53 in pez

 

Trip 2 took 5 and a half hours (x1 piss / pez stop), averaging 76 leptons and consumed 10.6 gallons of unleaded = 39.6mpg / £63.84 in pez

 

So by driving an average of 26% faster, I had a penalty which only equals a 13% increase in fuel consumption.

 

I'll shush now...

[CreepingJesus]

You do know that manufacturers fuel consumption tests are actually done on a rolling road in the equivilent of an automotive labaratory... The idea of a bunch of boffins with a can of petrol , a car on a test track with a pencil and paper is a wee bit out of date !

 

Erm, yeah about that... I'm obviously about 30 years out of time, and the idea of attaching any sort of tag of accuracy to any data from a rolling road, is pure anathema. They have their uses, but deadly accuracy isn't one of them. They're the devil's work I tells ya...

 

I see a lot of new trucks are automatics now, apparantly they're better on fuel than manuals. Only if driving tankers they say they're a nightmare because the sloshing round of the liquid confuses the box and it keeps changing gear to whatever it thinks is the right one.

 

...and so are those. The devil's work that is. Semi-automatics, based around non-synch 'boxes, and fully electro-pneumatically controlled. And utterly fucking useless. Hate the bastard things - as much use as tits on a fish.

They don't actually improve economy, what they do is even out all the drivers. So when the big fleets went over to them wholesale, their fuel figures improved. Despite quite a number of drivers' fuel economy getting worse.

I feel especially sorry for the tanker drivers up here who use Scannys; they have a bad habit of dropping into 2nd if you're trying to read slow traffic, and get round a roundabout/out of a junction. The result is often 2500rpm, kangaroo-ing, a panic to 5th or 6th, then a panic back to 4th. Where it should've been in the first place. Hilarious, with thousands of litres of whatever behind you.

Oh, and they're worse than useless in snow. Which is handy in Northern Britain.

[willswitchengage]

^Do you mean those ZF

things? I remember being shown around a new XF at the Leyland factory and being like OMG WHERE BIG KNOB SHAPED GEARLEAVER and it's just a dial on the dash saying DRN like on on new Jaaaaaag. I thought they were literally just an automated manual or are they a completely new design? Also thought they were an excellent idea, reduce driver stress + fatigue and you can programme in an eco shifting strategy. Here's a photo of a poor old Eastern European chap trying to get to the Cadbury factory this February

 

P1030582 by willswitchengage, on Flickr

 

Noticed they haven't caught on in 8x4s as much though

[fiatdaft]

Some american cars from the 50's onwards had dash mounted gear change buttons,so the principal isn't that new.

[CreepingJesus]

ZF Arsetronic*. I could rant for a fortnight about it, but no-one needs that. Ditto Scanny's system and Volvo/Renault's i-Shit.

The first time you're cruising along in a Volvo at 56, and the dashboard display flashes 'E+', then 'N' and the revs drop to idle is interesting. Hello i-Roll, you cheeky little scamp. And yet if I stick it in neutral at speed, it's called The Aberdeen Overdrive, and the law takes a very dim view.

If I could fleetingly return to the thread title, I'd urge anyone to take extreme care with Asda artics on the M876 and M9. Some of their drivers have forgotten the 'Safe And' bit, and gone with the 'Fuel Efficient Driving' bit, to the extent of setting the cruise control to 38 mph on the way back to Falkirk/Grangemouth.

I, and a few other drivers have 'had a word' with the offenders, and the TM's; but the drivers now have a league table to compete in, and some things (like safety of other road users) just get in the way.

 

*Besides, ZF are being economical with the truth in that vid; the Eaton SAMT was the first to use electro-pneumatic control of a twin-countershaft 'box. And that was in the late 80's when the first-gen semi-autos came in. ZF, you lying box of frogs. GIVE ME MY GEARSTICK BACK, CUNTS!!!!!! How it should be.

[worldofceri]

They don't actually improve economy, what they do is even out all the drivers. So when the big fleets went over to them wholesale, their fuel figures improved. Despite quite a number of drivers' fuel economy getting worse.

 

Isn't a big fleet's overall fuel figure an average of all their drivers anyway?!

 

What auto's are is relatively idiot-proof. We had a driver the other day refuse to take a hired truck out because "he'd never been trained to use a splitter box" (all ours are straightforward 6-speed). Prat.

[CreepingJesus]

^True, the big fleets are only looking at the bottom line, you're dead right. And for that, it's a valuable development.

But for me personally, I can't get on with the bloody things. I can't relax with them like I can with a manual 'box.

I 'proved' to Asda last year, that I was roughly 1mpg* better off over the day with a stick. The trainer tells me I need to use manual mode on the semi-autos more ! So why not just keep a few sticks for those of us as likes 'em? Out of their 105 units, precisely 1 isn't a teflon, and there's usually a queue for it.

Besides, they're far from idiot-proof; a competent idiot can cause all sorts of chaos with them! Especially in reverse, with an ArseTronic.

If I'd been the TM there, the twat who refused the motor with the split would've had his caricature on the wall of shame. It's surprisingly common: I had an Asda driver beg for the keys to 'his' Scanny, 'cos he couldn't handle a Merc Telligent Shift.

Well, enough for now - I'm off to see what the weather's like on Tyneside...wish me luck.

 

*FWIW, that's about 10%.

[warren t claim]

ZF Arsetronic*. GIVE ME MY GEARSTICK BACK, CUNTS!!!!!! How it should be.

 

The problem I've found with the AS box is that there's a MASSIVE delay when pulling away from a standstill causing me to literally shit my trousers at the thought of getting sideswiped at roundabouts, naturally I push the pedal down harder causing them to go into kickdown mode and therefore slower to accelerate while they lumber up the box one gear at a time. This coupled with the paranoid fear of the hill start control disengaging (happens to me all the time in Volvos for some reason) causing me to roll backwards (yep, hgv autos roll happily backwards and forwards in any gear) means that I dread driving them. Scanias Optilose system where you have all the benefits of an auto but with the extra controllability of having a conventional clutch falls down in practice because the only time I ever appreciate an auto is in a stop start traffic jam and the Scanny system seems to be the worst of both worlds. Whilst I'm in a whinging mood, I've never actually driven an HGV auto that always gave me reverse first time 100% of the time. Even the (slightly) better system used by Mercedes/Iveco is fundamentally flawed, the more laden they are the worse they behave, especially when you've been limited low to something like 51mph.

 

People slag Renner trucks and cars off all the time but the (allegedly unpopular) slap over and splitter box on my old Premium was a joy to use. MX55*** where are you now? (Nigeria I should imagine).

[worldofceri]

I never get reverse first time every time even in a manual. But that's 'cause I'm a spaz.

 

I'd forgotten about the delay when pulling away. I had a DAF auto the other week and the lack of control in a tight spot is bloody infuriating. I could easily have ended up kangarooing into some poor sod's car because of the temptation to push the pedal that bit harder. Didn't shit my trousers though. At least not literally.

[willswitchengage]

The trainer tells me I need to use manual mode on the semi-autos more

 

Sorry if this sounds silly but why don't you just stick it in semi-auto mode all the time if it's the bizarre decision making in auto mode that winds you up?

 

iPod-shift or whatever they call it in Volvo coaches seems to work fine from a passenger perspective, far quieter too than the whirry old B10 6HP planetary autos

 

Also enjoying that this thread has just turned into the HGV drivers moaning about their kit

[warren t claim]

The trainer tells me I need to use manual mode on the semi-autos more

 

Sorry if this sounds silly but why don't you just stick it in semi-auto mode all the time if it's the bizarre decision making in auto mode that winds you up?

 

 

 

Also enjoying that this thread has just turned into the HGV drivers moaning about their kit

 

It's a myth that I drive a truck, actually I'm a HGV Supervisor/Steering Wheel Attendant.

[CreepingJesus]

Sorry if this sounds silly but why don't you just stick it in semi-auto mode all the time if it's the bizarre decision making in auto mode that winds you up?

 

Right. I've no desire to turn this into a megapost, at this (or any other) late hour. So I'll try to keep it brief.

Manual mode cannot be used all the time, because the lag in the lower range is horrendous, and it's quite variable too. Also, I tend to be steering and trying to read the road at that point in time, so I can't always see the display to know what it's up to. Which is necessary, as trying to accurately block shift with a stalk can be a bit hit-and-miss.

 

iPod-shift or whatever they call it in Volvo coaches seems to work fine from a passenger perspective, far quieter too than the whirry old B10 6HP planetary autos

 

I've noticed that too, but then it's the 6-speed version and seems set up differently. After all, a coach has probly twice the power-to-weight ratio of an artic, so lazy shifts for passenger comfort will work fine.

I wonder if an i-Shit coach counts as an actual auto? Given that it's got no clutch pedal and many bus drivers have teflon only licenses, I could see why it might catch on in the PCV world . That and it being a Volvo of course.

 

People slag Renner trucks and cars off all the time but the (allegedly unpopular) slap over and splitter box on my old Premium was a joy to use. MX55*** where are you now? (Nigeria I should imagine).

 

Amen to that. Drove a few dCi Premium/Kerax with the slapper. Particularly miss (iirc) V956GGS; nicknamed Kermit, 'cos it was a green frog. Lovely old thing, and sipped diesel too.