Author Topic: What MPG are you getting from your Honda Jazz ?  (Read 175493 times)

guest1372

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Re: What MPG are you getting from your Honda Jazz ?
« Reply #150 on: March 02, 2018, 08:15:20 PM »
....maybe I don’t understand but wouldn’t the steering lock turn you into firey death pretty quick!😀
Don't take the key out....
--
TG

Jocko

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Re: What MPG are you getting from your Honda Jazz ?
« Reply #151 on: March 02, 2018, 08:25:53 PM »
69 Kg is not bad. I could afford to lose more weight than I could strip out of the car!
I wouldn't contemplate EOC as the steering gets too heavy and you can lose the brakes after a while. Steering lock won't come on unless you remove the key, but there is no need to go past the Acc  position anyway. P & G is useful. I make use of P & G with DFCO, but a bit of coasting in neutral with the engine on is a handy hypermiling tool.
I have a ScanGauge E fitted to my OBD II port and it returns all sorts of useful information.


Fell Viper

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Re: What MPG are you getting from your Honda Jazz ?
« Reply #152 on: March 02, 2018, 11:47:34 PM »
Don't take the key out....
--
TG

That can’t be right surely? With the ignition off doesn’t the steering lock activate? I know is that did on older cars!

Fell Viper

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Re: What MPG are you getting from your Honda Jazz ?
« Reply #153 on: March 02, 2018, 11:53:49 PM »

I have a ScanGauge E fitted to my OBD II port and it returns all sorts of useful information.



What’s DFCO! (I’ve been in the wilderness a while!)
I’d love a scan gauge, but as this is a cost saving excercise I can’t justify it! I looked at the blue tooth Obd2 plug ins that work with an app,  but I don’t want to get burned and don’t know enough aboht them to comit.

P&G for me has been really valuable, once I’ve reached the top of the penines there are long stretches where I can coast for ages. It can add another 10 mpg on by the time I reach work!

Jocko

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Re: What MPG are you getting from your Honda Jazz ?
« Reply #154 on: March 03, 2018, 08:49:31 AM »
DFCO is Deceleration Fuel Cut Off. Most modern fuel injected vehicles (including the Honda Jazz) shut the fuel off entirely when you remove your foot from the accelerator. Provided the speed/gear selected is sufficient to keep the engine revs above tick over (actually around 1800 - 2000 rpm) then you use no fuel whatsoever. This is where the ScanGauge comes in handy (Mk 1 Jazz doesn't have instantaneous mpg on the dashboard display). On steeper descents it is better to remain in gear and use no fuel than coast in neutral, and use tick over fuel. The secret of good fuel management is to balance the use of the two, and this is where an instantaneous mpg gauge earns its keep.
Regards steering lock. Try it for yourself. While parked, turn the ignition off but do not remove the key. You can then turn the steering from lock to lock (not easy with no power steering or vehicle movement) and you will see the steering lock doesn't function. However, for EOC you just need to turn the key back one notch, to the Accessory position. That turns the engine off but won't allow you to remove the key.

guest1372

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Re: What MPG are you getting from your Honda Jazz ?
« Reply #155 on: March 03, 2018, 11:11:05 AM »
You can use the cheap OBDII dongles for this purpose, I can link my <£5 Elm327 Bluetooth dongle to my phone, I can see the instantaneous mpg and put it on a graph plus log it to a file if I wish. It's quite interesting to put the engine load graph against the mpg graph and throttle position.  The other one that varies a lot is the timing advance but that is not really something you can use for analysis while driving.  Can't say I bother doing this much as just driving in a sensible manner is enough without the distraction of a second screen.  The dongle also comes in handy for checking/clearing fault codes if needed.
Some cars leave the OBD port powered all the time but the Jazz turns it off so you can leave it plugged in all the time without draining the battery.

And re: the key - the lock only re-engages when the key is removed but as above you would never switch off completely, (power steering and brakes are more desirable than saving a few pence) it won't be an issue.
--
TG

d2d4j

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Re: What MPG are you getting from your Honda Jazz ?
« Reply #156 on: March 03, 2018, 11:23:30 AM »
Hi TG

I’m sorry, are you sure the odb2 is powered off fully when keys removed

We use an AA cargenie and it is able to communicate to the odb2 plug from their mobile app on phone

I know because currently the car has not been used since yesterday and I have a warning over low voltage from car genie. Guess this means I need a new battery

Many thanks

John

d2d4j

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Re: What MPG are you getting from your Honda Jazz ?
« Reply #157 on: March 03, 2018, 11:26:27 AM »
Sorry, here’s a screenshot of battery warning

Many thanks

John

Jocko

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Re: What MPG are you getting from your Honda Jazz ?
« Reply #158 on: March 03, 2018, 01:10:25 PM »
Sometimes when I open the door, the ScanGauge comes on, so the OBD II port must have power to it without the ignition being on.

guest6489

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Re: What MPG are you getting from your Honda Jazz ?
« Reply #159 on: March 03, 2018, 05:41:54 PM »
Mine 2011 ES shows a bit over 49mpg for the last 6000 miles. I think it's generally about 10% over so 45ish in real money. It's mostly pottering about town doing short trips. Best I've seen on the dash is 64.9, but that was hard work. It really needs thrashing to get it to show under 40. To many cameras now to see break my land speed record on Christmas morning and see what high load fuel consumption is. Might do that in Germany this summer...

guest1372

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Re: What MPG are you getting from your Honda Jazz ?
« Reply #160 on: March 04, 2018, 02:09:36 AM »
Hi TG

I’m sorry, are you sure the odb2 is powered off fully....
Well in my GD the OBD dongle led extinguishs when I take the key out (in the MX5 it stays lit, maybe it's on a timer but it runs the battery down from experience).  The MK2 or 3 may be different. My dongle does not contain it's own battery.
--
TG

Fell Viper

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Re: What MPG are you getting from your Honda Jazz ?
« Reply #161 on: March 06, 2018, 11:54:28 AM »
What apps are people using with their obd2 port widgets?

Some great info here guys thanks!

Not sure about coasting down hill in gear, surely the gear ratio even in 5th causes some engine breaking? In neutral I can pick up some speed

Jocko

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Re: What MPG are you getting from your Honda Jazz ?
« Reply #162 on: March 06, 2018, 12:39:32 PM »
Not sure about coasting down hill in gear, surely the gear ratio even in 5th causes some engine breaking? In neutral I can pick up some speed
That is where you have to manage it. If you are descending a hill where you will have to brake then leave it in gear. If you have a long shallow descent where braking is not required, stick it in neutral. One road I use regularly (because it is so fuel efficient) has a couple of short sharp climbs, then some lovely descents. To begin with the road is steep and twisty, so I use 4th and sometimes 3rd gear. This gives me engine braking AND enough revs to keep DFCO active. Then there is a long descent with a bend 1/3rd of the way down. I stick in 5th then as I round the bend I select neutral and let the speed build. At the end there is a gentle rise to a 30 mph limit so I coast in neutral to there (well in the summer I do. In the winter, with wet roads, I have to add power about 50 yards from the 30 zone). It is all about managing the inertia, and be aware, the heavier the vehicle, the better it coasts!

Fell Viper

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Re: What MPG are you getting from your Honda Jazz ?
« Reply #163 on: March 07, 2018, 03:32:56 PM »
Definitly aware of weightbaiding gliding, but I have that many steel ascents   working out better loosing weight.

Ultimately it seems we’re in terrotory where mods are dependant in usage.

It’s why I also want smaller wheels, I don’t do enough consistent flat runs to make larger ones work

Fell Viper

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Re: What MPG are you getting from your Honda Jazz ?
« Reply #164 on: April 11, 2018, 12:41:22 PM »
I make use of P & G with DFCO, but a bit of coasting in neutral with the engine on is a handy hypermiling tool.




I’ve altered my driving style to make the most of DFCO and already noticed a difference. I’m still coasting for the longer sections (3 looong ones) as otherwise the engine breaking in fifth fouls me so bad I end up having to give some gas again negating any advantage. And the idling fuel work out better over. Longer coast.

I have an obd2 dongle to an app on my phone which is a revelation! A lot of really handy monitors.

Cars seem to have changed so much in the last 20 years that I’m having to relearn lot. I spent a long time in the no car wilderness as I didn’t need one! I’m not even that old! 😂

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