Obviously ive been depressed about the 30-35 mpg my Carina is returning in normal driving after the easy 55 mpg I used to get from the Charade so I decided to run a little experiment and I followed just a few of the more easily applied economy tips.
The one that really stood out to me was the coasting, which in an auto like mine works very well as there isnt much engine braking to speak of. Ive found that I can coast for half a mile at a time in places that I never really thought to and loose very little speed, maybe 5 mph.
Its amazing how much you stay on the throttle when infact you dont need to at all.
Ive also been trying very hard to limit my throttle openings more and while it takes a little bit longer to get up to speed, once im near the limit, its quite easy to maintain the speed without much throttle at all. My car will roll along at 62-65 even up and down moderate hills with barely a touch on the throttle.
Im going to read the handbook in a minute to work out what the ideal crusing speed is ( max torque ). This will be useful on long journeys.
The result though of just these ametuer changes and a little effort - 47 mpg brim to brim. I could quite believe that because that is a mix of A-roads, country lanes and town work. Im hoping to break the 50 mpg barrier on a run up to Newark at the end of the month. Ive been unable to find official figures for the auto, but the manual is supposed to do 51.4mpg at a constant 55 mph when brand new, so if I can beat that ill know Im really getting somewhere.
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www.car4play.com/forum/post/index.htm?f=2&t=1349
Have fun!
BTW - what do you mean by 'coasting' in an automatic?
Last edited by: Old Sock on Fri 21 May 10 at 14:19
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Coasting - foot off the throttle, revs drop to just above idle. No sense putting it in neutral as sticking an old trans back into drive on the move may be a bit unwise.
The proviso of course is that you dont hold people up, but thats easily done and if you speed up too slowly, that is counter prouctive because you want to be feathering the throttle asap.
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Two things kill economy, acceleration and braking.
Avoid both and you are laughing.
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Stu describes the revs dropping to idle on releasing the pedal. Do all autos do that? It surprised me when an S60 Geartronic courtesy car I was driving did it, but that was years ago and I probably haven't driven a true auto since. I remember not liking it, because it made it hard to regulate speed around town using engine braking, as I do a lot. The possible benefits to fuel economy didn't occur to me.
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Thats good economy Stu and remarkable from a manual older saloon let alone an auto, i'd put up with the choke being a bit of a pain and leave well alone there.
The pick up and my old MB coast just like Stu's Toyota, i can't get anywhere near those figures though.
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Well if your of a mind to GB, take a figure by which to compare, then try a period of really trying to coast whenever possible. With the torque on your MB, Im sure it will work even better on light throttle. Its worth it as an experiment just to see what you can do.
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Just make sure none of you mimsers pull onto a main road, crawl away and get rear ended. If you cant afford the fuel to drive it properly use the bus..
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Why is driving at the legal limit in an economical way mimsing???
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Sorry, I thought you were talking about people driving below the speed limit when the limit would be safe.
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Maybe you should read the thread then. Note the proviso of not holding people up... its actually more economical to drive at 60 on an NSL road than potter along at 40.
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"its actually more economical to drive at 60 on an NSL road than potter along at 40"
Not in any car I've ever driven. 40-45 has always been the most economical speed. I can get 40+ mpg from my 3 litre petrol at these speeds, increase to 60 and it dive-bombs.
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>>Not in any car I've ever driven. 40-45 has always been the most economical speed. I can get 40+ mpg from my 3 litre petrol at these speeds, increase to 60 and it dive-bombs.<<
Depends on the car. Gearing, engine, weight, so many factors. 60 is deffo the best speed for my car as its turning over 2000 rpm in overdrive whereas at 45 its in 4th at 2500 but needs a fair chunk of throttle if it meets a decent incline. At 60 it is far less of a problem. Presume OD is direct drive hence the economy savings.
The real gains are in the coasting though.
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That Navy bloke, he do like a leg pull,
and the trouble with the MB is that when accelerating you get to a certain speed which we won't go into she sort of fires up a second time and really picks her skirts up and the exhaust sounds lovely and the engines beating like she's living and it just keeps pulling, and then you have to use the ample brakes amply....and thats why i get between 17 and 25 mpg.
I've tried Stu i really have but those two horns still raise me grey stubble, it's the wrong car for economy.
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Well it was a genuine thread, could do with leaving that mimser rubbish to the current designated thread :-) let them argue it out there.
Most cars are wrong for economy, its just an interesting exercise to find out whats possible, but I know what you mean about cars with a bit of go - my Carina isnt a naturally fast car anyway so it seems harsh to thrash it too much. Makes it easier to roll along.
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I too have a Carina E, 1.6 auto and would LOVE to get 50+ mpg from it. I can only get 31mpg which in fact is what the official figure is for urban driving. However, even on longer runs it never seems more than this. The official figure for a constant 56mph is about 52mpg (I will check this in the morning).
According to the HJ review of this car (with the lean burn engine) it needs to be driven at 'high revs with a small throttle' which I've never been able to understand.
You can't genuinely 'coast' in an auto unless it was put in neutral which I wouldn't want to do with an auto.
I don't know if your Carina is the same stu, but my petrol gauge bears no relation to what is actually in the tank. The tank holds 13 gallons so you would think that each quarter of the guage indicates say 3.25 gals. But the way the needle moves I would say that the 'top' quarter equals five galls, then 4, then 2 and the last quarter to empty another two. This being the case it is difficult knowing how much fuel has been used - even trying to fill the tank to the brim is hit and miss.
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My Carina is the previous model, known as the II, which has a much older engine. I dont go by the fuel gauge at all - I filled up when the light came on and I only got 10 gallons in which is 3 short of empty. Ive found brim to brim fairly accurate so long as you replicate the process each time.
Im not sure how a lean burn engine can run at high revs in an auto, seems at odds with the instincts of the autobox which would be to change up to a high gear.
I imagine the constant 56 mph figure for my old banger is around the 45 mark ( manual is 53, checked today ) but ive beaten that in mixed driving which includes alot of stopping and starting.
Its a bit of fun if nothing else.
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No car is more economical at 60 than at 40mph.
The end.
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Yeah ok, Im sure you researched that really well. Im assuming your a motoring engineer to make such a statement and since you must be to be so sure, care to explain why?
If you drive a car in second gear at 40, id bet you my life savings that its less economical than the same car in top gear at 60.
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>> If you drive a car in second gear at 40
But nobody is saying drive at 40mph in 2nd are they? If top gear at 60mph is possible then why not 3rd or 3th at 40mph?
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"No car is more economical at 60 than at 40mph.
The end."
The Toyota Carina Special Edition Holy Grail appears to be.
If a car uses more fuel at 40 than it does at 60 when resistance is exponentially increased, then there is something seriously wrong with it at 40.
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>> "No car is more economical at 60 than at 40mph.
>>
>> The end."
>>
>> If a car uses more fuel at 40 than it does at 60 when resistance
>> is exponentially increased, then there is something seriously wrong with it at 40.
>>
It can be a matter of gear ratios and engine efficiency, i.e. if an auto locks out at 60mph which also coincides with the rpm that max torque is produced it may be more economical than slushing around between higher ratios at 40.
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Like I said, something seriously wrong with it.
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I've seen a few reports of 'scientific' tests of cars at various speeds over the past 30 years.
Without exception the best MPG is at around 30mph and there is a steady decline after that, usually worse for the more aerodynamically challenged vehicles.
I presume Stu's Carina has a 'lock-up' once it is doing about 50mph in overdrive (usually feels a bit like anothe gear change and stops the engine revving more than the roadspeed) which may well reduce the inefficiency of the slushmatic, but the rapidly increasing wind resistance will outweigh this.
Driving at 40 on NSL roads is, however, the most hateful form of driving known to (wo)mankind!
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www.whatcar.com/car-news/fuel-economy-making-every-gallon-count/introduction/233124
Few pages about the test here in 2008 - there's a wee chart on the 3rd page that if you squint at you can see the reducing MPG as a function of speed.
WC runs a test like this every 5 years or so (you'll see the lazy journalism recycling the same topic every year for petrol vs diesel, etc).
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Thanks for the info.
In my car, maintaining 40 requires more revs and throttle than maintaining 60 on account of the overdrive coming in at 52. Im not sure quite what the direct drive bit means but Im sure I read somewhere that it has to do with the torque converter which I understand to be the source of much inefficiency in the transmission. Maybe someone more technical can explain what the overdrive does.
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Hilux is most economical at 55 to 60, below that it struggles to stay in 4th lock up unless the road is flat, above that obviously it's shifting too much air.
So much depends on gearing, with an auto you've got to travel at the most comfortable speed to stay in the highest gear that locks up.
Some manuals are now so high geared i think the 40 mph accepted thing is obsolete, the BMW 320CD in 6th is doing 1500 rpm at 60 or maybe 70 (few weeks since i've been in it), if you wanted to travel slower you'd have to change down....though i suppose an instant readout would be needed to confirm, the lower gear at lower speed might well balance out the greater volume of air to shift in the higher gear.
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30-40mph isn't the speed at which the car is necessarily happiest to drive - it is simply where the least amount of fuel is used to travel the same distance.
From graph on the WC link above, the LR Freelander is a 2.2 turbodiesel auto (red line on chart) - the MPG still falls with every 10mph increment, but the slope (rate of fall) levels out at 60-70mph presumably when top (6th?) engages.
There's every possibilty that trying to maximise MPGs in this way shortens the life of the engine, but that's so much harder to measure.
Last edited by: Lygonos on Sat 22 May 10 at 10:47
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The overdrive is simply a higher gear much as a manual box's 5th (or 6th).
An analogy of a torque converter would be like floating a bowl inside another bowl with the gap between them filled with viscous liquid - if you spin one bowl (eg. with the 'engine'), the other bowl will also spin, although slightly slower. The 2nd bowl is attached to the transmission/wheels - this is how torque goes from engine to wheels without a normal clutch.
A 'lock-up' mechanism physically attaches the 2 bowls together so that if you spin one, the other spins at the same speed with less loss through slippage/in the fluid.
Dunno if that makes it easier to visualise or if you're now thinking about the washing up... :-)
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Has to be noted that a Freelander is not a very aerodynamic example, are there any for family sized autos?
So the OD is in effect a direct drive much the same as top gear in a manual is, presumably to stem the efficiency losses at crusing speed?
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A slight change of direction here.
I guess that legislation dictates that newspaper ads for all new cars - including those in the 50k plus range - have to devote most of their text to the various mpg figures, often with little mention of anything else.
Surely anyone spending that amount isn't likely to fret about their fuel bills, or be too concerned about green issues.
Last edited by: Clk Sec on Sat 22 May 10 at 11:16
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I think it depends on how many miles you do. I have very wealthy customers who still buy the diesel over the petrol even though they seem to spend copious amounts on other rubbish.
Its usually the rich who do fret about green issues because they can take the penalties but still take on the green cause.
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I think 'the rich' tend to have cars with 15+ gallon fuel tanks - putting £100 into a car even raises the eyebrows of a Plutocrat I bet!
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> putting £100 into a car even raises the eyebrows
There's something magical about that number though. In all the time i've owned it the 728 has never taken less than £85 to fill. Fine, no complaints.
On Wednesday 21st April it took £100.59. That's the one fill up that's going to stick with me until i'm old :-(
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Yes, I remember when Nelson tipped went up to 50p a packet. Ten bob in old money!!
I digress.
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Just looking at the official figures for the Carina E, they say simulated urban driving (no average speed given) is 35.3mpg for a 1.6 petrol 4-door manual and 31.7mpg for the auto. At a constant 56mph it's 56.5mpg manual and 53.3mpg for the auto.
I would be surprised if I got 40mpg at 56mph in the auto let alone 53!!
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"I have very wealthy customers who still buy the diesel over the petrol...."
As well as economy (remember they could have got rich by economising) they like, as I do, the 500-600 miles between fill-ups if they do a lot of motorway miles. Rich or poor, no-one likes motorway service areas.
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Also these past few weeks I've been driving with the overdrive off and I feel that fuel economy has improved. This may also prove the 'high revs small throttle' I talked about earlier. When not in overdrive the revs are higher at the same speed than when in overdrive. This may seem like it would waste fuel but I don't think it does, something to do with engine load, there was a thread on here (or maybe the other place) about this some time ago. I put overdrive back on if I'm doing more than say 55mph.
Also if you are hovering at around 50mph with overdrive on it is forever going into overdrive then out then back again which must affect economy.
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I've been playing this game with the diesel CRV this week. 52.5 mpg so far on the computer, which won't be far off. No coasting either (but plenty of calculated slowing down on the over run). This is 20% better than 'normal' driving and 50% better than real press-on style.
After 17 miles of country roads coming home last night the discs were barely warm.
Getting up to speed quickly doesn't seem to hurt it unless I hold the revs - change up well before 2500 and the acceleration is little worse, and economy much better.
Keeping a decent gap 200 or 300 metres when it's flowing) helps; I don't have to brake when the traffic slows, and often hit roundabouts just right when the traffic in front has bunched and waited a few seconds.
For maximum economy I don't use cruise control on undulating roads - too often it will be using lots of fuel to avoid losing 3 or 4 mph before a crest, which you can pick up again for nothing on the other side.
As for baulking other traffic, picking a careful line round bends and not slowing down unnecessarily keeps them at bay!
Last edited by: Manatee on Sat 22 May 10 at 13:10
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>> For maximum economy I don't use cruise control on undulating roads - too often it
>> will be using lots of fuel to avoid losing 3 or 4 mph before a
>> crest, which you can pick up again for nothing on the other side.
>>
I bet the drivers trying to maintain a steady speed behind you really enjoy your speed up, slow down driving style.
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>>>I bet the drivers trying to maintain a steady speed behind you really enjoy your speed up, slow down driving style.
If it annoys then tough I say. There's far too much of those that perceive themselves as *good* drivers demanding minimum speeds/standards from others to suit their required progress.
I came across a big engined 07 plate BMW doing 43mph on a local NSL B-road the other day. Thought it odd, but not really annoying. Guess what.... I just passed him. No stress and I'm on my way.
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Indeed, ive never found slow drivers annoying. Most NSL roads roun my way have enough overtaking oppotunities that its just a case of a short wait. Its also easier to pass a car doing 40 than one doing 55. Takes less space and cars accelarate faster at low speeds. So id rather Maureen in her Morris Minor potters along as it means I can get past easier.
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>>I bet the drivers trying to maintain a steady speed behind you really enjoy your speed up, slow down driving style.
I don't drive particularly slowly, and I'm talking small variations - less than most people would notice anyway (unless they are using cruise control and following closely).
My point was that the extra fuel used by using cruise to maintain a steady speed can be disproportionate to the benefit.
If they want to maintain a steady speed (a form of OCD in my opinion on anything other than a motorway) then they need to keep a decent gap, then they'll have no problem.
Until we are only allowed slot cars controlled by a central computer, we are all going to have to fit in with each other rather than whingeing about people who aren't doing exactly what we want, aren't we? ;-)
Last edited by: Manatee on Sat 22 May 10 at 14:06
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Doesn't the fuel consumption even itself out? My CC cuts the fuel on downhill bits of road, I would not be surprised if your car depreciated more on your journey than the fuel you save.
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I never drive at a single speed anyway. I drive by road and traffic conditions, where I am in the journey and if I'm on time, the purpose of the journey, on a whim maybe and perhaps its even affected by the music I have on, company/conversation in the car and the sun. All these factors vary during a journey.
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> I drive by road and traffic conditions
Does that include the traffic behind you, or only the traffic in front of you?
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>>>Does that include the traffic behind you, or only the traffic in front of you?
Oh yes and the traffic that I've yet to see that migh be round the next bend. The possibility of walkers and horses in certain areas... everything really.
And if you're behind me and don't like it but can't get past then either your car is too slow or I'm already at a sensible max for the road... which is highly likely :-)
Last edited by: Fenlander on Sat 22 May 10 at 14:43
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Mine doesnt given that it isnt worth anything really :-) As Rattle said, you pay more for a colour than I did for a whole car.
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>> Mine doesnt given that it isnt worth anything really :-) As Rattle said, you pay
>> more for a colour than I did for a whole car.
>>
I worked hard to be able to, and realise how fortunate I am.
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As I said, I've been playing the game this week. But you can't argue with the difference between 41mpg and 52. Did I say 20% better? Make that 25%; and I still have the same cars in view in front of me at the end of my journey.
About £570 a year at current fuel prices, if I keep it up. Hardly trivial; and I can still break free now and again on a nice bit of empty road if I want to. And fuel cost is real cash money. However much or little the depreciation, saving fuel won't increase it.
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Unfortunately skilled smooth drivers like myself can't improve enough to make the effort worthwhile. :-)
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It's curious how people make such a big fuss about holding up road traffic for a few minutes, yet the subject never gets a mention with reference to pedestrians.
Don't dawdle along window-shopping, get a move on.
Don't walk two abreast when there is someone trying to get past, pull over.
Check whether there is anyone walking along the pavement before strolling out of the shop doorway.
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>> It's curious how people make such a big fuss about holding up road traffic for
>> a few minutes, yet the subject never gets a mention with reference to pedestrians.
>>
I stunned four chattering women into silence a few days ago, they were stood in a supermarket doorway almost blocking it. A loud "If you spread out a bit you can block the whole door" was effective in moving them. Caused Mrs ON to disown me for a while too, :-)
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>> >> It's curious how people make such a big fuss about holding up road traffic
>> for
>> >> a few minutes, yet the subject never gets a mention with reference to pedestrians.
>> >>
>> I stunned four chattering women into silence a few days ago, they were stood in
>> a supermarket doorway almost blocking it. A loud "If you spread out a bit you
>> can block the whole door" was effective in moving them. Caused Mrs ON to disown
>> me for a while too, :-)
>>
I hate it!
Shopping as entertainment - not BUYING anything, just poncing about at the shops because you have nothing better to do on a saturday, just mimse-walking about the local mall or down the high street...
GET OUT OF MY WAY, LOSERS! I have things to BUY! A List, god damn you! I know where I want to go, and to buy what, NOT waste a few hours of my time in aimless wandering.
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I have things to BUY!
Tranquilisers?
:-)
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Takes us back to that other thread where the OP mentioned people who get off trains or escalators... and then STOP!
Just a quick note to the impatient amongst us (seems to be a lot of 'em btw)... its illegal to board a train if someone is trying to get off at the same time at the same door... one of those more obscure bylaws don't you know!!
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...its illegal to board a train if someone is trying to get off at the same time at the same door...
This was well-observed by commuters in London when I used the tube regularly in the 1980s.
But in other parts of the country, people still try to board trains while someone is trying to get off.
There's a parallel here with the traffic in London.
Most drivers know the 'rules' and everyone gets along as well as they can.
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Getting really good economy - Old Sock
