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Old 24 May 2007 | 01:19 PM
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Default Autoexpress -- MPG article

Hi all,

Been a while since we've had an MPG thread, so here's one with a difference. I'm told that Autoexpress (?last week) had an article about how to get better MPG by revving harder -- unlikely though that might sound!

Has anyone on here got it? If so, could you scan it and post it, please, or alternatively, give us the gist of what it said?

Thanks,

Andrew
Old 24 May 2007 | 01:33 PM
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Originally Posted by abc
Hi all,

how to get better MPG by revving harder -- unlikely though that might sound!

This idea I like !
Old 24 May 2007 | 01:34 PM
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I havn't seen or read it myself, but the harder you rev, the more fuel you use. Nothing will ever change that, so I look foward to reading the article.
Old 24 May 2007 | 01:40 PM
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Originally Posted by chrispurvis100
I havn't seen or read it myself, but the harder you rev, the more fuel you use. Nothing will ever change that, so I look foward to reading the article.
Something to do with engine mapping, I think.
Old 24 May 2007 | 01:48 PM
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Originally Posted by abc
Something to do with engine mapping, I think.
labouring the engine uses more motion lotion

Old 24 May 2007 | 02:01 PM
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Haven't seen the article, but revving the engine higher does incur more pumping losses and there's more internal friction. However the engine may breathe better at certain speeds, and labouring an engine at low revs is not good for MPG either! Hope someone can scan it and post it up for scrutiny!
Old 24 May 2007 | 02:02 PM
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Originally Posted by abc
Something to do with engine mapping, I think.
Yes, I suppose you could map the ecu to run lean at high revs.........but then your engine would go bang!
Old 24 May 2007 | 02:05 PM
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Wasn't this on Top Gear years ago, or was it 5th Gear?

Anyway, Tiff did a study that concluded that using say 3 quarters throttle up to 60mph from stand still used less fuel than slowly accelerating (Quarter throttle) to get to 60mph,as you get to a steddy throttle travel sooner (constant 60mph) by hitting 60 sooner.
Old 24 May 2007 | 02:10 PM
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Originally Posted by stilover
Wasn't this on Top Gear years ago, or was it 5th Gear?

Anyway, Tiff did a study that concluded that using say 3 quarters throttle up to 60mph from stand still used less fuel than slowly accelerating (Quarter throttle) to get to 60mph,as you get to a steddy throttle travel sooner (constant 60mph) by hitting 60 sooner.
exactly better to hit your cruising speed quicker as the old cimbustion engine is very economical once at cruising velocity
Old 24 May 2007 | 02:10 PM
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There was a test on brainiac where Mr Hammond tested various types of driving in a caterham.
Out of 'driving like a granny', 'accelerate and coast' and 'driving like schumacher', the granny technique won hands down.
I always take a note of my mpg in every vehicle I drive/own. Have always found that low revs/throttle opening to be the most efficient.
Old 24 May 2007 | 03:54 PM
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At a constant speed below 2,500 rpm (e.g 60 mph), on a 120 mile run even a WRX can achive 35mpg easy!

Key to good fuel consumption
1) no hard breaking
2) excelerate slowly and reduce turbo boost
3)no hard cornering or sudden ants in pants motion
4) Turn off air-con and stereo
5) keep speed within the legal limits (drag factor)


It's always a good one to argue against the greens that a WRX can achieve a similar mpg to a people carrier TD!

But then again, most people on this forum seem to boast about how bad the fuel consumption is and seem intent to achieving the worst possible mpg
Old 24 May 2007 | 04:00 PM
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Originally Posted by mikepaul

But then again, most people on this forum seem to boast about how bad the fuel consumption is and seem intent to achieving the worst possible mpg
That's rubbish. Your talking cr@p.






STIlover
(I never get above 21mpg)
Old 24 May 2007 | 04:25 PM
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Originally Posted by stilover
That's rubbish. Your talking cr@p.






STIlover
(I never get above 21mpg)
I can get 290 to 300 miles on a full tank driving like a granny, is this good or normal, I drive a highly modified WRX with over 400BHP, im getting more from a full tank now than when it was standard...
Old 24 May 2007 | 04:27 PM
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was one of your mods a 100L tank?
Old 24 May 2007 | 04:32 PM
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Originally Posted by wrx-kris
was one of your mods a 100L tank?
If it is, fuel only costing me 50p ltr Cool i wonder if garage knows this, i get 105 mile up to 1st mark on gauge.
Old 24 May 2007 | 04:33 PM
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thats a commone outcome of remappings isnt it. I noticed my sti with a tsl 333 is now better mpg than the sti ppp for example.
Old 24 May 2007 | 04:37 PM
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Originally Posted by AllyJ
thats a commone outcome of remappings isnt it. I noticed my sti with a tsl 333 is now better mpg than the sti ppp for example.
Dam thought i was getting cheep v-power, but when the foot gets heavy where has all my fuel gone i had a full tank 5 mins ago
Old 24 May 2007 | 06:57 PM
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Originally Posted by mikepaul
At a constant speed below 2,500 rpm (e.g 60 mph), on a 120 mile run even a WRX can achive 35mpg easy!

It's always a good one to argue against the greens that a WRX can achieve a similar mpg to a people carrier TD!
Agreed -- I managed nearly 37 mpg once. The look on people's faces when they criticise you for having a thirsty car and you tell them this is another reason why scoobies are such fun -- though not the principal one, I grant!

Originally Posted by stilover
Anyway, Tiff did a study that concluded that using say 3 quarters throttle up to 60mph from stand still used less fuel than slowly accelerating (Quarter throttle) to get to 60mph,as you get to a steddy throttle travel sooner (constant 60mph) by hitting 60 sooner.
I think the Autoexpress article was arguing something like this -- hit the loud pedal hard when accelarating from standstill through the gears (though I guess important to keep off boost).

Anyone able to scan the article and post it, please?
Old 24 May 2007 | 07:21 PM
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Originally Posted by wrx-kris
was one of your mods a 100L tank?
Old 24 May 2007 | 08:13 PM
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I have heard of research done like this before. It was concluded that brisk acceleration to your constant cruising speed was best for economy. I never heard the explanation as to why though.
Old 24 May 2007 | 08:16 PM
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i have just binned the article yesterday

very interesting and looks like it will work, but not that practice for everyday driving

IIRC what they were saying is nail the throttle, the ecu should map the fueling perfect, back off compleatly and coast, useing no fuel, nail the throttle again and the ecu should map the fuel correctly, then back off the throttle so you kind of "seesaw" down the road
Old 24 May 2007 | 09:49 PM
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I really cannot believe some people have achieved >30mpg (36 lol..!) in their WRX's..!

How are these people checking their consumption I wonder..?

The best I've ever managed was 26mpg and average 22, which is 90% steady around town driving..!
Old 24 May 2007 | 10:36 PM
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I managed 37mpg once in my MY99 UK Turbo a year ago. 50mph for 100miles, filled up before and after. It was also very, very hot.
Number of liters/4.545, then divide the mileage by the number of gallons used.
Old 24 May 2007 | 11:37 PM
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Originally Posted by jasonius
I really cannot believe some people have achieved >30mpg (36 lol..!) in their WRX's..!

How are these people checking their consumption I wonder..?

The best I've ever managed was 26mpg and average 22, which is 90% steady around town driving..!
I struggle to believe this aswell mate. I average 21 mpg in my wrx.
Old 25 May 2007 | 08:36 AM
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i managed 282 miles to a full tank quite regular when travellng up from london to newcastle every month last year

think the classics have a 50 litre tank? around 10/11 gallons?

used to stop at the same service station every time, then fill up again and use the next full tank to blast home at warp factor 6

round the doors i usually get about 200 miles to the same tank
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