Author Topic: Reserve tank  (Read 22918 times)

Roddy0000

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Reserve tank
« on: September 10, 2018, 10:20:36 PM »
Hi, today mileage said 0 miles left when running on empty, does anyone know how many miles or fuel that are left after that point  before I run out of fuel. Think the fill up was about 47 litres. Many thanks.

ColinB

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Re: Reserve tank
« Reply #1 on: September 11, 2018, 07:47:10 AM »
Firstly, don’t rely on the accuracy of the range prediction, it’s only an estimate. I’ve been surprised to see how much it varies during a journey for no apparent reason. Sudden changes up and down by tens of miles are not unusual, so when it reads zero all that means is that you’re somewhere near the bottom of the tank. Zero readings on different occasions are quite likely to give you different amounts of fuel remaining, which means there is no standard answer to your question.

Secondly, why run the tank right down ? It only creates unnecessary anxiety.

Roddy0000

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Re: Reserve tank
« Reply #2 on: September 11, 2018, 08:39:32 AM »
Firstly, don’t rely on the accuracy of the range prediction, it’s only an estimate. I’ve been surprised to see how much it varies during a journey for no apparent reason. Sudden changes up and down by tens of miles are not unusual, so when it reads zero all that means is that you’re somewhere near the bottom of the tank. Zero readings on different occasions are quite likely to give you different amounts of fuel remaining, which means there is no standard answer to your question.

Secondly, why run the tank right down ? It only creates unnecessary anxiety.
I don’t normally run the tank down but was surprised on this occasion how quickly it showed empty.

Jocko

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Re: Reserve tank
« Reply #3 on: September 11, 2018, 08:53:26 AM »
Think the fill up was about 47 litres.
You did well. According to your manual the tank is only supposed to hold 40 litres!

peteo48

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Re: Reserve tank
« Reply #4 on: September 11, 2018, 11:10:49 AM »
Thinking that myself!

Typo? 37 litres?

culzean

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Re: Reserve tank
« Reply #5 on: September 11, 2018, 11:25:37 AM »
Hi, today mileage said 0 miles left when running on empty, does anyone know how many miles or fuel that are left after that point  before I run out of fuel. Think the fill up was about 47 litres. Many thanks.

Normally it will register zero miles left when you get to reserve ( about 6 or 7 litres)  Before that point the miles to go figure will vary quite a lot depending on the current rate you are using fuel ( injector open times as seen by ECU ) so if you are hurtling down a steep hill you may see figure increase, if you are climbing that same hill the figure will decrease.  I never let my tank get much less than half empty, there is simply nothing to be gained by doing so unless you want to increase the level of cor"tisol in your body....   when you get to zero on miles to go you may have 40 to 70 miles left, Honda are very conservative ( generous) on their reserve, unlike a mini or a fiat which may give as little as 15 miles warning of complete fuel deficit. 
« Last Edit: September 11, 2018, 11:37:15 AM by culzean »
Some people will only consider you an expert if they agree with your point of view or advice,  when you give them advice they don't like they consider you an idiot

Ozzie

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Re: Reserve tank
« Reply #6 on: September 11, 2018, 11:31:38 AM »
I've done 30 miles on 0 range before and put in 35 litres to refill.

At the end of my working day, I have a 70 mile drive home, mainly motorway, if the range is under 100 miles, I will refill before I start the trek home. However if it shows 110 miles, it will frequently drop to 0 before I get home, mainly due to the motorway/dual carriageway combination of fast roads and roundabouts, so more slowing and accelerating than had it been one long road without roundabouts.

ColinB

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Re: Reserve tank
« Reply #7 on: September 11, 2018, 11:53:20 AM »
... the miles to go figure will vary quite a lot depending on the current rate you are using fuel ( injector open times as seen by ECU ) so if you are hurtling down a steep hill you may see figure increase, if you are climbing that same hill the figure will decrease. 
Not what it says in the manual. Page 124 "Range ... Shows the estimated distance you can travel on the remaining fuel. This distance is estimated from the fuel economy of your previous trips". The effects of opening/closing of injectors caused by road conditions, driver input etc. should be smoothed out by using average consumption data, so the range displayed shouldn't vary in the way it does. There's probably a reason for the inconsistent display but that doesn't sound like it.

Jocko

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Re: Reserve tank
« Reply #8 on: September 11, 2018, 11:59:51 AM »
I only have the fuel gauge and the low fuel light on my Mk 1. I am seldom out after dark so tend to refuel when my warning light comes on. I am never far from a filling station. If I am going a considerable journey, or a trip where I may get stuck in traffic, I will fill up once I get below a quarter tank. The only reason I run so low is it improves the accuracy of my fuel calculations.
My ScanGauge gives a miles to empty figure, but I never use it, don't trust it and seldom even look at it. That is what I feel an on-board display would do for me as well.
« Last Edit: September 11, 2018, 01:15:02 PM by Jocko »

peteo48

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Re: Reserve tank
« Reply #9 on: September 11, 2018, 12:34:26 PM »
It's funny how people have different policies about refuelling. I tend more to the Culzean approach. In a modern car I start getting twitchy when the miles to refuelling goes down to 100. I have to say I've never run out of fuel.

I might have mentioned a pal of mine in another post but he tends to run on virtually empty all the time. He puts a tenner's worth  in when the light goes on. If he's going a bit further he might go mad and put £20 in.


A Nissan Leaf would suit him - he never has more than about 80 miles range! He swears he has never run out of petrol though so he's spent his entire driving career living on the edge!

Roddy0000

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Re: Reserve tank
« Reply #10 on: September 11, 2018, 03:09:07 PM »
Think the fill up was about 47 litres.
You did well. According to your manual the tank is only supposed to hold 40 litres!
Sorry that should have read 37.

JohnAlways

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Re: Reserve tank
« Reply #11 on: September 11, 2018, 04:29:50 PM »
I ran out of petrol once, in my Morris Minor about 1973. Wife and I walked about six miles to get a gallon of petrol (and buy a can to put it in). Never again! :)

peteo48

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Re: Reserve tank
« Reply #12 on: September 11, 2018, 05:08:49 PM »
Was your wife still speaking to you after this escapade John? :D

John Ratsey

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Re: Reserve tank
« Reply #13 on: September 11, 2018, 09:22:18 PM »
Sorry that should have read 37.
Which means that you had 3 litres (about 2/3rd of a gallon) remaining in the tank. At 45 mpg this gives 30 miles but if you have some difficult urban driving it may only be 20 miles. It's useful to know what buffer you have with the system showing zero miles remaining but it's not something to explore regularly.
2022 HR-V Elegance, previously 2020 Jazz Crosstar

JohnAlways

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Re: Reserve tank
« Reply #14 on: September 12, 2018, 09:07:22 AM »
Peteo48, well she remembers the Phrase "round the next corner"! I tried to encourage her by saying "it's round the next corner" (but the garage was shut on Sundays"! So I said "well there's another one not far away, around the next corner"!  I seem to remember we got engaged the next weekend, she was still complaining about the blisters she got (she wasn't wearing suitable walking footwear) and when I say it's not far away I often get the reply "What around the next corner"! :)

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