Author Topic: What MPG are you getting from your Mk1 Honda Jazz ?  (Read 33111 times)

istvantamas

  • New Member
  • Posts: 5
  • Country: gb
  • My Honda: Honda jazz 2004 and honda civic 1.6i-vt
Re: What MPG are you getting from your Mk1 Honda Jazz ?
« Reply #255 on: October 26, 2018, 08:43:14 AM »
2004 1.4dsi 151k miles

47,5-54,5mpg according to the comp.

1.4dsi honda jazz 2004
1.6i-vt honda civic 1990 (ee9)

springswood

  • Bob the Jazz
  • Approved Member
  • *
  • Posts: 10
  • Country: gb
  • My Honda: Jazz GE3 1.4 Sport 2008
Re: What MPG are you getting from your Mk1 Honda Jazz ?
« Reply #256 on: October 30, 2018, 10:31:39 AM »
I just bought a 2008 Jazz 1.4 Sport (GE3) with 106k miles.

I topped up and reset the mpg meter.
After 120 miles of mostly town driving the dash said 43.2 mpg, toppimg up again I made it 38.5
Another 230 miles including more motorway and a new air filter the meter showed 45.7 but I made it 42.4

So a service is in order when I can get to my brother's workshop.

I don't know why the computer should be exaggerating so much.

I notice it's short runs from cold that really kill the mpg so I might try some 0-20w oil.

UPDATE
Fairly sure I have the EGR valve problem. I bunged some redex in, no change. From reading here I tried an 'Italian tune' revving well over 3500 - very alien to the way I drive. After the first try I saw 50+ for the first time, but then back to the 40s. Just done it again. Only for a few miles of dual carriage way. I reset the mpg A few more miles at a steady 50mph and it seemed to be heading for 64mpg. With a final couple of miles on A roads and traffic free town I ended at 68. On the way back a steady 45 got me over 70mpg.

So the carb cleaner and gasket are on order. Many thanks I wouldn't have imagined it could make such a difference.
« Last Edit: November 04, 2018, 12:49:44 PM by springswood »
Indecision is a terrible thing.
Or is it? What do you think?

smilertoo

  • Approved Member
  • *
  • Posts: 60
  • Country: gb
  • My Honda: 1.39l Honda Jazz 2004 Ice Blue - 45mpg max/40mpg normal
Re: What MPG are you getting from your Mk1 Honda Jazz ?
« Reply #257 on: November 10, 2018, 09:35:31 PM »
I cleaned the EGR valve but the benefit was very short lived, does that mean i need a new valve or should i try and clean the entire EGR system and not just the valve?

peteo48

  • Approved Member
  • *
  • Posts: 1209
  • Country: gb
  • I have entered the Jazz Age
  • Fuel economy:
  • My Honda: 2017 Honda Jazz 1.3 SE CVT Tinted Silver
Re: What MPG are you getting from your Mk1 Honda Jazz ?
« Reply #258 on: November 11, 2018, 10:40:50 AM »
I wouldn't worry too much about the computer reading. It's within the range I've experienced over 3 Jazzes now. My recent fill was an actual 39.2 and a recorded 43. I've got to the stage where 4 mpg over optimistic is a reasonable bench mark. I record mine faithfully on Fuelly.com on the brim to brim method. To be honest that's because I'm a bit OCD about these things. I've often thought a quick check of the computer, knock off 4 mpg, and I'd be pretty much bang on.

I have noticed that, on long journeys, the percentage that the on-line computer is out is less. There are, on this site, people with the technical know how to explain this.

springswood

  • Bob the Jazz
  • Approved Member
  • *
  • Posts: 10
  • Country: gb
  • My Honda: Jazz GE3 1.4 Sport 2008
Re: What MPG are you getting from your Mk1 Honda Jazz ?
« Reply #259 on: November 11, 2018, 10:43:15 AM »
Good question smiler. There is a link on one of the EGR threads here to a YouTube clip showing how to clean the pipework from the manifold. It looked straightforward.

I haven't done mine yet, I'm still waiting for the gasket to arrive.
Indecision is a terrible thing.
Or is it? What do you think?

springswood

  • Bob the Jazz
  • Approved Member
  • *
  • Posts: 10
  • Country: gb
  • My Honda: Jazz GE3 1.4 Sport 2008
Re: What MPG are you getting from your Mk1 Honda Jazz ?
« Reply #260 on: November 11, 2018, 10:50:26 AM »
Thanks Peteo48. I have started a fuel mileage record.

That said the display is useful as a guide to what helps improve economy. For instance there's a long hill I often use here and I wonder if it's best to go up it in fourth or fifth.
« Last Edit: November 11, 2018, 10:54:34 AM by springswood »
Indecision is a terrible thing.
Or is it? What do you think?

culzean

  • Approved Member
  • *
  • Posts: 4170
  • Country: england
Re: What MPG are you getting from your Mk1 Honda Jazz ?
« Reply #261 on: November 11, 2018, 11:44:44 AM »
Good question smiler. There is a link on one of the EGR threads here to a YouTube clip showing how to clean the pipework from the manifold. It looked straightforward.

I haven't done mine yet, I'm still waiting for the gasket to arrive.

The only purpose of the EGR is to cool combustion at high revs by allowing exhaust gas into inlet manifold ( to reduce oxygen in the ingoing charge ) this reduces the nitrogen oxides in exhaust.  What does the damage to performance is when valve is open ( stuck ) at revs below 3000, this can cause lumpy running, lack of power and stalling. Even when it is working normally it reduces performance at higher revs, it  is better for performance if the valve never opens, but not so good for environment.
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

peteo48

  • Approved Member
  • *
  • Posts: 1209
  • Country: gb
  • I have entered the Jazz Age
  • Fuel economy:
  • My Honda: 2017 Honda Jazz 1.3 SE CVT Tinted Silver
Re: What MPG are you getting from your Mk1 Honda Jazz ?
« Reply #262 on: November 11, 2018, 12:25:56 PM »
Just thought I'd check my mpg as measured by the computer. On trip B - which I have kept at the same setting since I bought the car - it is showing an overall mpg, over around 1800 miles, of 48.4. The actual is 44.1 so around 10% out.

The 4 mpg figure almost seems a constant with my Jazzes. The best ever mpg I had in my last Mk2 Jazz was 56.2. I remember that the computer showed a tad over 60 mpg. In this case a smaller discrepancy in percentage terms but still 4 mpg!

A bit like that "the answer is always 42" thing from Hitch Hikers Guide to Galaxy (think it was that).

John A

  • Approved Member
  • *
  • Posts: 75
  • Country: gb
  • My Honda: 2014 Honda Jazz ES+
Re: What MPG are you getting from your Mk1 Honda Jazz ?
« Reply #263 on: November 11, 2018, 12:38:15 PM »
A bit like that "the answer is always 42" thing from Hitch Hikers Guide to Galaxy (think it was that).

What's the answer to life, the universe, everything ?

springswood

  • Bob the Jazz
  • Approved Member
  • *
  • Posts: 10
  • Country: gb
  • My Honda: Jazz GE3 1.4 Sport 2008
Re: What MPG are you getting from your Mk1 Honda Jazz ?
« Reply #264 on: November 12, 2018, 08:12:17 AM »
Fair point culzean. What I was  thinking was if the pipes from the manifold are mucky then when the EGR valve does open more crud might be getting in again.
Indecision is a terrible thing.
Or is it? What do you think?

springswood

  • Bob the Jazz
  • Approved Member
  • *
  • Posts: 10
  • Country: gb
  • My Honda: Jazz GE3 1.4 Sport 2008
Re: What MPG are you getting from your Mk1 Honda Jazz ?
« Reply #265 on: November 14, 2018, 11:30:43 AM »
Did the EGR yesterday. Good job as there was no gasket  :o. No massive difference in mpg (45.7 by the comp after a few shortish urban trips) but seems to be a bit smoother to drive.
Indecision is a terrible thing.
Or is it? What do you think?

culzean

  • Approved Member
  • *
  • Posts: 4170
  • Country: england
Re: What MPG are you getting from your Mk1 Honda Jazz ?
« Reply #266 on: November 14, 2018, 12:29:11 PM »
Did the EGR yesterday. Good job as there was no gasket  :o. No massive difference in mpg (45.7 by the comp after a few shortish urban trips) but seems to be a bit smoother to drive.

Did you zero the trip before test drive with EGR fixed ? The mpg display is very sensitive when trip is reset, but will hardly change when 100+ miles on trip no matter how you drive. This is because mpg computer is averaging any instantaneous changes in mpg over a larger number of miles.
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

springswood

  • Bob the Jazz
  • Approved Member
  • *
  • Posts: 10
  • Country: gb
  • My Honda: Jazz GE3 1.4 Sport 2008
Re: What MPG are you getting from your Mk1 Honda Jazz ?
« Reply #267 on: November 14, 2018, 01:27:50 PM »
Yes I zeroed the trip so it is an average over a small mileage (about 30 miles).

Which reminds me. I tried zeroing it before two trips up that mile long hill I mentioned. Not going above fourth gear it showed 33 mpg at the top. Keeping in 5th all the way 35.something. I was lucky with the traffic and was able to maintain the 40 mph limit both times. So 5th is better even though my foot is a lot further down on the pedal.

Reading around since I understand it's to do with BSFC (brake specific fuel consumption) and possibly lower pumping losses with the throttle open. But then as we said when I was studying physics an ounce of observation is worth a pound of theory.
(Yes it was a long time ago, though a gram being worth a kilo isn't beyond the realms of possibility.)
Indecision is a terrible thing.
Or is it? What do you think?

culzean

  • Approved Member
  • *
  • Posts: 4170
  • Country: england
Re: What MPG are you getting from your Mk1 Honda Jazz ?
« Reply #268 on: November 14, 2018, 01:48:32 PM »
Pumping losses ( pistons pulling against a throttle butterfly ) are a problem with petrol engines but not diesel ( diesel engines do not have a throttle as such but vary the amount of fuel injected to vary the power).   When the Civic 8th gen > ( and MK3 Jazz ) go into 'atkinson mode at low revs Honda do some magic by holding the throttle butterfly open and inlet valves open on the 'compression' stroke to pump some mixture back into inlet manifold,  lowering the compression ration and power output.  This reduces pumping losses.  The great hope for smaller engines with turbo is that the throttle would have to be opened more, giving reduction in pumping losses,  but the gains never materialised and the nitrous oxide levels went up over larger normally aspirated engines ( back to the drawing board )...
« Last Edit: November 14, 2018, 02:19:59 PM 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

springswood

  • Bob the Jazz
  • Approved Member
  • *
  • Posts: 10
  • Country: gb
  • My Honda: Jazz GE3 1.4 Sport 2008
Re: What MPG are you getting from your Mk1 Honda Jazz ?
« Reply #269 on: November 19, 2018, 10:26:29 AM »
Did a couple of 100+ mile mostly motorway trips this weekend. After the first mpg showing over 48. Fairly happy, then I found the tyres were between 24 and 28 psi. With correct pressures I got home showing 50.4 mpg. That's cruising between 60 and 70.

Seems all's well with my Jazz  :D
Indecision is a terrible thing.
Or is it? What do you think?

Tags:
 

Back to top