Author Topic: Reserve tank  (Read 22919 times)

Jocko

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Re: Reserve tank
« Reply #30 on: September 17, 2018, 05:55:46 PM »
I regularly take the long way round to get better mpg at the cost of going further and using more petrol! As I have said elsewhere, returning good mpg (the game), is more important than saving money on petrol.

Just an aside, how do I insert a hyperlink, but with text?
Quote
if/when the road is reopened.

andruec

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Re: Reserve tank
« Reply #31 on: September 17, 2018, 06:16:58 PM »
I regularly take the long way round to get better mpg at the cost of going further and using more petrol! As I have said elsewhere, returning good mpg (the game), is more important than saving money on petrol.

Just an aside, how do I insert a hyperlink, but with text?
Quote
if/when the road is reopened.
Technical way:
* Type (url=???)<Insert your text here>(/url)

But:
* Replace '()'s with '[]'s
* Replace question marks with the URL (contents of browser address bar).
* Your text replaces the <> bit.

So an example using round brackets to avoid it being picked up by the forum software as a URL would be:(url=http://somedomain.com/document)This is the url text(/url).

The less technical way is to type the text, highlight it then click the button with an image of the planet Earth and a document. Then append =??? after the first 'url'.

But I is a programmer so I do not do stuff the untechnical way  :P
« Last Edit: September 17, 2018, 06:20:28 PM by andruec »

Jocko

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Re: Reserve tank
« Reply #32 on: September 17, 2018, 06:46:11 PM »
Thanks. I'll copy that and keep it to hand.

John Ratsey

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Re: Reserve tank
« Reply #33 on: September 17, 2018, 09:00:44 PM »
Still, although 10% better mpg is nice, driving 70% further means the diversion is costing me more.
I would assume that it takes several miles (more if the weather turns cold) for the powertrain to warm up and run and optimum efficiency. So potentially little over half of your 12 mile journey is with the powertrain running most efficiently while the proportion of the longer route may be more than 3/4. Set the big screen to show the trip mpg and you will see how low it starts and then gradually improves. I would like thermostatic louvres on the engine comparment to assist the warm-up process but this is unlikely to happen until low temperature starts become part of the standard mpg testing.

You can expect to see even better mpg if you can potter along the slow lane at 55 mpg (my HR-V can give 60 mpg under this situation) or ever slower. Don't forget that last year's Jazz Land's End to John O'Groats trip on one tank was done at 40 mph.
2022 HR-V Elegance, previously 2020 Jazz Crosstar

andruec

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Re: Reserve tank
« Reply #34 on: September 17, 2018, 10:29:50 PM »
You can expect to see even better mpg if you can potter along the slow lane at 55 mpg (my HR-V can give 60 mpg under this situation) or ever slower. Don't forget that last year's Jazz Land's End to John O'Groats trip on one tank was done at 40 mph.
That's how I drive motorways anyway for the most part. I tend to set the cruise control to 60mph and will tolerate down to 55 when following HGVs especially if it's busy. Anyway I don't believe that even driving at 80mph would significantly reduce a journey time of 20 minutes. Any gains would likely be lost in the congestion at M40 J10 anyway.

But your point about engine warm up could definitely be a factor. The reported mpg usually drops a couple of mpg fairly quickly and doesn't start recovering until half way along the old route. So yeah, the drive train is possibly spending twice as long in a fully warmed up state. It'd be interesting to see a live trace of both routes though. I'm an efficient driver who hardly ever uses his brakes despite bends and some hills on the A road so seeing the losses/gains of both routes would be interesting.

I think there might be greater elevation changes on the A road (the M40 seems to follow a valley) but of course overall the elevation changes are the same and the A-road isn't particularly hilly. No where around here is.
« Last Edit: September 17, 2018, 10:32:41 PM by andruec »

Jocko

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Re: Reserve tank
« Reply #35 on: September 18, 2018, 07:05:01 AM »
Did an accurate check of my speedo, against the GPS, this morning. At 30 mph the GPS reads 28 mph and at 20 the GPS flicks between 17 and 18 mph. I won't be out of the town until Saturday, so I will check the higher speeds then.
The way I have my steering wheel set it obliterated 60, 70 and 80 mph, but I will hunker down a bit and get an accurate reading.
My ScanGauge E sits on top of the binnacle and if I position the wheel to allow sight of the indicator telltales then it obscures the top of the speedo. For my driving the telltales are more important than the 60, 70, 80 markings.

ColinB

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Re: Reserve tank
« Reply #36 on: September 18, 2018, 08:47:41 AM »
Did an accurate check of my speedo, against the GPS, this morning.
Just to be a bit pedantic here, you're not doing an accurate check of your speedo, what you're doing is comparing one system of measurement against another, each of which has it's own sources of error. Reasons for speedo inaccuracy are well documented (chiefly the legislation requiring it to over-read, but also factors affecting wheel diameter such as tyre wear), but car satnavs are not exactly precision instruments either. Accuracy can be affected by the number of satellites the unit can "see", the quality of the signals, whether those signals are being obscured by or reflected off nearby objects, road gradients, and consistency of speed (it calculates speed by measuring time between position fixes so there's a lag when accelerating or decelerating).The satnav is undoubtedly more accurate than the car speedo when driving straight & level at constant speed in open country, but it would be wrong to consider that it's always absolutely correct.

Whilst on the subject of accuracy, I'm always intrigued by statements that the car's onboard computer doesn't give accurate MPGs and then talking about devices like Scanguage. That sort of device uses the same data as the car's computer and does the same calculation, so why should it be more accurate ?

Jocko

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Re: Reserve tank
« Reply #37 on: September 18, 2018, 09:03:58 AM »
When I say accurate, it is as accurate as I need it. It is not as if I record both instantaneous readings and then compare them. I look first at one, then at the the other so it's as accurate as that. I also travel at a constant speed in an open location so minimise errors from buildings etc.
The ScanGauge is more accurate, as every top up you add a correction to the error which you don't do with the on-board. But to be pedantic, it is only more accurate, not completely accurate. Of course, neither is a computed figure, gleaned from one tank of fuel. The figure beside my avatar is a computed figure from (currently) 56 fill ups, so that is pretty accurate.

peteo48

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Re: Reserve tank
« Reply #38 on: September 18, 2018, 10:34:45 AM »
You can expect to see even better mpg if you can potter along the slow lane at 55 mpg (my HR-V can give 60 mpg under this situation) or ever slower. Don't forget that last year's Jazz Land's End to John O'Groats trip on one tank was done at 40 mph.
That's how I drive motorways anyway for the most part. I tend to set the cruise control to 60mph and will tolerate down to 55 when following HGVs especially if it's busy. Anyway I don't believe that even driving at 80mph would significantly reduce a journey time of 20 minutes. Any gains would likely be lost in the congestion at M40 J10 anyway.

As I've got older, I have moved more to this style of driving largely because it is much less stressful. I'll use cruise if I can but the motorways where I live are usually incredibly busy. My overall approach is to drive around 60 mph until or unless I find a slow moving bunch and then I will usually accelerate up to 70 mph to get past quickly.

Jocko

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Re: Reserve tank
« Reply #39 on: September 18, 2018, 01:08:12 PM »
My overall approach is to drive around 60 mph until or unless I find a slow moving bunch and then I will usually accelerate up to 70 mph to get past quickly.
I tend to do similar. Until I come upon the slow moving bunch, when I slow down and join them. The thing is, my longest drive is about 40 miles, of which 23 miles is motorway/dual carriageway, and I have all the time in the world. Different drivers have different priorities.

peteo48

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Re: Reserve tank
« Reply #40 on: September 18, 2018, 01:37:18 PM »
On the slow moving bunch, it all depends on where I am as regards the next turn off. I find the "accelerate like mad only to have to cut into the nearside lane before you turn off" brigade pretty ridiculous. They used to annoy me but I now try to maintain a zen like calm :)

andruec

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Re: Reserve tank
« Reply #41 on: September 18, 2018, 03:24:32 PM »
On the slow moving bunch, it all depends on where I am as regards the next turn off. I find the "accelerate like mad only to have to cut into the nearside lane before you turn off" brigade pretty ridiculous. They used to annoy me but I now try to maintain a zen like calm :)
Although I also find the opposites quite amusing. People who drop in behind me a couple of miles from the junction (braking in order to do so) despite there often being plenty of space in front of me. A lot of them will also then tailgate me until the junction.

Some drivers (typically the 'fast brigade') simply have poor acceleration sense. They can drive fast..but mostly only in a straight line and often misjudge their timing.

Skyrider

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Re: Reserve tank
« Reply #42 on: September 18, 2018, 03:42:22 PM »
Accelerator control is as important as clutch control, accelerating up to the braking point for a stop or problem that can be seen from way back is the sign of a driver to keep clear of or treat with caution.

Skyrider

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Re: Reserve tank
« Reply #43 on: September 18, 2018, 04:28:09 PM »
I posted this on another forum yesterday.

I had a similar one driving from Newcastle to Edinburgh up the A1 yesterday. A BMW (obviously) varying his speed from 50 to 60mph in the 60 limits and 60 and 70 in the 70 limits for no apparent reason. When I was eventually able to overtake him in a dual carriageway section he accelerated, obviously not aware that there is a more powerful Jazz around. He almost accelerated into the back of a car in lane one with this antic and then gave up and slowly dropped back as I pottered along on cruise control at the speed limit.

Driving standards were being discussed.
« Last Edit: September 18, 2018, 04:31:35 PM by Skyrider »

Downsizer

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Re: Reserve tank
« Reply #44 on: September 18, 2018, 05:35:11 PM »
That implies that the car thinks I can drive nearly 500 miles on one tank.
I've had 480 miles between fills on one occasion, after long duel carriageway trips, and the refill was 38.5 litres, so I think 500 miles is certainly achievable.  The gauge was down to one bar and not many miles remaining, but on another occasion I drove 10 miles or so beyond the zero miles remaining.  I don't think anyone should worry about running it down to zero miles remaining, provided of course you know where the next filling station is!

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