HELP: only 28mpg!!!

[rodnick]

Hello everyone
Just bought 55 reg 1.4 sport cvt from Crown Honda with 34000 miles. It is only doing 28 MPG. I did 90 miles motorway and 140 in London and used 36 l petrol. Please help me find out what is happening any advice will be helpful
thank you

[SuperCNJ]

Your mpg will go down this time of year when the air is cold as the engine has to compensate by increasing fuel to balance the increase in oxygen. Also, you're likely to be using more of the heating elements on the car which consumes fuel.

Other things that may affect it is firstly how heavy your right foot is,  the last time you serviced your car and also the pressure in your tyres. But being in London its not surprising your mpg is low... I'm getting about 31mpg in our manual 1.4 sport, so in a CVT I'd expect around 29mpg.

HTHs 

[Chabree]

Try Shell V-Power, it may help... I am trying it first time myself but I don't have any data to prove it yet.

Good luck!

[culzean]

The recent cold weather will really knock fuel consumption, but you could try cleaning out the system with a couple of tanks of Shell 'V power' or BP 'Ultimate' petrol, or try putting injector / system cleaner in the tank for a couple of fill-ups.  Is there any way to check if spark plugs have been changed since car was new?

[E27006]

To test your fuel consumption:

Brim the tank,

Drive 100 miles on the Motorway at a light throttle with 60 mph on the speedometer.

keep the throttle position steady, don,t get competitive & race opther Cars.

Rebrim the Tank and calculate yoiur mpg

[Jazz-E]

Chabree, let us know how you get on with the Shell petrol.

[Jazz-E]

Rodnick, see this post, you will see that after a service and a long run i improved my MPG from 31 to about 45.

http://clubjazz.org/forum/general-honda-discussion/fuel-economy/60/
 

[rodnick]

thank you all for your responses
 I bought an injector cleaner checked tyres and driven motorway on 60 only and I managed to get 45.22 mpg
I am reliefed that nothing is wrong with the car
Thank you all once again

[Chabree]

Some update for the Shell V-Power petrol:

Before V-Power:
41, 42, 43, 36, 41 (MPG)
(mixture of city and motorway driving)

V-Power
42MPG (one full week of city driving)

48MPG (one full week of motorway driving)

NB, my Jazz is a 2009 model, so not sure whether this affects the GD model or not.

My view is that the V-Power is worth it.  I worked out the cost difference and I think I am still saving.  With V-Power, I felt the car is a lot more powerful (PS I don't work for Shell just in case you wonder!  )

[culzean]

I've written before on this site about the benefits of using 'Ultimate' or 'V power' in the Jazz GD with its high compression ratio. I have actually seen up to 10% fuel economy increase in like for like driving using these fuels over 95RON, as well as the car feeling livelier. These fuels also have more cleaners and upper cylinder lubricants in them.

The Honda handbook actually says for European Jazz use 'minimum' of 95RON to avoid knocking (pre-ignition).  By using a better fuel the engine managment system is allowed to not worry about pre-ignition and to concentrate on using ignition timing settings that will optimise combustion and give both more flexibility and power as well as better economy.

[danny100]

Hi guys,if there anymore doubt, i suggest to get it, "plug in" check out by the diagnostic equipment, see its any Faults code come up...mind you if lamda(oxygen)sensor, not 100% surely it d affect the fuel consumption

good luck,

[Pine]

My local Tesco store has recently started selling 99 octane.  Is this the same as V-Power or ultimate, has anyone tried it?  Greenergy who supply Tesco petrol make great claims for it on their website:
 http://www.greenergy.com/tesco_99_octane/index.html

[Jazz-E]

I have just posted an update on a similar topic and using the V-Power, I have found no difference in MPG, although this includes a summer to winter difference.  I am hoping that if I continue to use this and retest in the summer, I could increase the MPG.

I have come across this site which you can calculate your MPG and cost per mile.  You can see for yourself if it makes it cost effective to swap.

http://www.torquecars.com/tools/uk-mpg-calculator.php

I would also add that the V-power does appear to have made the Jazz more responsive.  I always thought I had a point in 3rd which did not pick up well, but now with the V-power that has gone.

[joejazz]

First time ive used the Jazz for a while on a decent run last week, i filled up to the neck to start........from Leeds to Flambourough and a couple of days up and down the coast pleasuring...then a run back to Leeds (on the hurryup) and i returned on a fill up to the neck 49mpg.............out going was full of gear for the caravan opening........so im thinking thats good............ Joe

[culzean]

Filled the tank yesterday, trip was on 420 miles and I put in 31.6 litres (6.9 gallons) till pump cut out - that's 61mpg using normal BP 95 RON. Mileage is mixed town and 'A' road commuting, about 250 miles per week.

The last best mpg figure I had on tank of 95 RON was 58mpg, I don't know how much of the increase in mpg is due to the fact that a few weeks ago I replaced the manual gearbox fluid with Castrol SMX-S 75-80 + molyslip, but the gearbox is certainly smoother and quieter - or it could just be due to warmer weather - I have used aircon quite a bit, which doesn't seem to have affected consumption  too badly.

Car is GD 1.4SE with 70K on the clock, it has never been into a garage for service in last 5 years (and interestingly has never had tappets adjusted either - which Honda claim is vital to keep mpg and emissions up to scratch).