Author Topic: Reserve tank  (Read 22880 times)

Jocko

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Re: Reserve tank
« Reply #15 on: September 12, 2018, 09:32:20 AM »
we got engaged the next weekend
Your lucky. I was taking my girlfriend and her parents (who I hoped would become future in-laws), for a Sunday afternoon run. I had filled up with petrol, but on a quiet country lane I broke down. Turned out I had run out of petrol! Her father and I walked to the nearest town for petrol, while the ladies stayed with the car. We got home okay, but the next day I found I had a serious leak from my fuel pump, and the tank was now empty once again.
The upshot of it all was, a few weeks later I got dumped. She was the love of my life too.
Many years later we got back in contact and she told me it was her mother who talked her off me! Bl**dy Ford.

richardfrost

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Re: Reserve tank
« Reply #16 on: September 12, 2018, 02:33:11 PM »
Many years later we got back in contact and she told me it was her mother who talked her off me! Bl**dy Ford.

I wonder if you had a lucky escape. Imagine that person as your mother in law!

mikebore

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Re: Reserve tank
« Reply #17 on: September 15, 2018, 07:21:09 AM »
Have a look at this thread:

https://clubjazz.org/forum/index.php?topic=8270.msg41133#msg41133

Summary:

Warning light came on with 25 miles remaining. I drove on until zero bars.
At zero bars miles remaining was zero, and I filled up. The tank took 37.29 litres, so litres remaining was 2.7 litres, or about 30 miles.
So total miles from warning light to empty would be about 25+30=55 miles

I expect some repeat tests would give some different results depending on circumstances...but I don't intend to do it again  :D
« Last Edit: September 15, 2018, 08:11:50 AM by mikebore »

peteo48

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Re: Reserve tank
« Reply #18 on: September 15, 2018, 10:10:06 AM »
Just on this topic - and possibly raising an old chestnut - does anybody know if the idea that, if you let your tank run down to nearly empty, a load of crud will be sucked into your injectors, is true or false?

Jocko

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Re: Reserve tank
« Reply #19 on: September 15, 2018, 11:31:56 AM »
This was once a problem, but now, in the UK, the petrol we buy is clean and free from "crud", as you call it. Fuel tanks are either plastic or, if steel, coated internally. The days of rust forming inside old fuel tanks has long gone.
Any water that is in the fuel (very little in these days of sealed fuel systems), collects in the lowest part of the tank. The fuel pick up position is designed to avoid picking up water.
The Jazz (Mk 1 at any rate), has a fuel filter designed to trap any foreign bodies, and only needs changing every 72,000 miles or 6 years. However, recommendations I have read says that if the fuel pressure is within it's limits then there is no need to change the filter. As it is inside the fuel tank this is no bad thing. The filter requires a good deal of work to replace. Unless I experience fuel issues I will not be looking near my fuel filter.



ColinB

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Re: Reserve tank
« Reply #20 on: September 15, 2018, 03:16:32 PM »
Just on this topic - and possibly raising an old chestnut - does anybody know if the idea that, if you let your tank run down to nearly empty, a load of crud will be sucked into your injectors, is true or false?
False. If you think about it, the fuel pump suction inlet must be at the lowest point of the tank: if it wasn’t you wouldn’t be able to use the fuel at the bottom of the tank anyway. So if you have any solid contamination or water in there, that’ll actually be the first stuff to go through the pump and into the injectors, not the last.

peteo48

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Re: Reserve tank
« Reply #21 on: September 16, 2018, 10:45:22 PM »

Over 90 miles from fuel light coming on and 50 from when needle hit zero in this old Honda Accord.

And I start worrying ages before the light comes on!

andruec

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Re: Reserve tank
« Reply #22 on: September 17, 2018, 09:12:30 AM »
I'm rather intrigued by mine at the moment. Due to a road closure I'm having to divert my commute and instead of 12 miles of A road at 50mph it's now almost entirely dual carriageway and motorway at 60mph with some delays at the A43/M40 junction where the idle stop comes into its own.

Although this has increased the distance by nearly 50% to 20 miles it has improved the reported fuel consumption. It had been showing around 54mpg over the summer but is now showing 58mpg. What's intriguing me is that after a week the fuel gauge is currently showing just under three quarters (for 200 miles) and the remaining distance is showing as 280 miles.

That implies that the car thinks I can drive nearly 500 miles on one tank. Given that it's ultimately the same journey (Brackley to Banbury) the overall rise/fall should be the same so this seems to imply that 60mph is a far more efficient cruising speed (almost 10%) than 50mph which surprises me.

The delays at the A43/M40 (up to fifteen minutes) are additional delays with no equivalent on my normal route so I think that is helping to show the value of idle stop.

Jocko

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Re: Reserve tank
« Reply #23 on: September 17, 2018, 09:30:56 AM »
I find that my most fuel efficient speed is 60 mph on the speedo (about 53-54 mph on GPs).

peteo48

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Re: Reserve tank
« Reply #24 on: September 17, 2018, 12:41:40 PM »
Purely speculation here but I'm thinking back to the old official methods of measuring mpg. If I recall correctly, there was a 56 mph figure and I seem to recall this was touted as the most efficient cruising speed for most cars.

I remember a work colleague with whom I shared cars with commuting to work back in the late 1970s. He used to drive along the M3 at a constant 56 and got some pretty remarkable figures out of his old Morris Marina.

Jocko

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Re: Reserve tank
« Reply #25 on: September 17, 2018, 02:05:21 PM »
The figures used to quote mpg at 56 mph and I was always of the impression that any UK car would probably be optimised for that speed. Rightly or wrongly it made sense to me.

Kenneve

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Re: Reserve tank
« Reply #26 on: September 17, 2018, 02:18:32 PM »
I find that my most fuel efficient speed is 60 mph on the speedo (about 53-54 mph on GPs).

I'm surprised that Jocko finds the speedometer error so high.
If I cruise at 60 mph my satnav reads 58 mph and at 30 mph it reads 29 mph.

VicW

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Re: Reserve tank
« Reply #27 on: September 17, 2018, 03:22:41 PM »
I'm surprised that Jocko finds the speedometer error so high.
If I cruise at 60 mph my satnav reads 58 mph and at 30 mph it reads 29 mph.

I find the same, My speedo reads 2mph high across the board. I think in theory a speedo is not allowed to be more more than 10% inaccurate according to the Construction and Use Regulations hence most Police Forces applying a 10% + 2mph rule to speeding. No I don't know where the 2mph comes from.

Vic.

peteo48

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Re: Reserve tank
« Reply #28 on: September 17, 2018, 04:30:55 PM »
The error on mine is 3 mph at 70. It's the only time I tend to look at the GPS speed and it consistently shows 70 mph on the speedo as 67.

andruec

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Re: Reserve tank
« Reply #29 on: September 17, 2018, 04:38:55 PM »
I find that my most fuel efficient speed is 60 mph on the speedo (about 53-54 mph on GPs).

I'm surprised that Jocko finds the speedometer error so high.
If I cruise at 60 mph my satnav reads 58 mph and at 30 mph it reads 29 mph.
It will vary (to some degree) based on your tyres. As they wear the speedometer should become less (or more?) accurate. My experience isn't so bad as Jocko's though. 60mph is currently about 57mph and 50mph is currently 47mph according to GPS.

I also remember the 56mph figure for fuel consumption which I always assumed came from 90kmh. Thinking about it the revs seem to be the same on my car for 60 as for 50 (1,800) so presumably the CVT must be choosing a slightly higher ratio.

Still, although 10% better mpg is nice, driving 70% further means the diversion is costing me more. Currently everyone is waiting to see if/when the road is reopened. I recently discovered that it's the county council paying for it and since Northants council is effectively bankrupt it doesn't sound too good :(
« Last Edit: September 17, 2018, 04:46:51 PM by andruec »

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