Hi Everyone,

Im new to this forum and new to owning a Honda Jazz its only been a month since i brought it, I apologies if this topic has been covered but after a search I didn't find the answer I was looking for.

I have a Honda Jazz 1.4 i-DSI, manual 52 Reg with 44k on the clock, full service history, I had the car fully service a few weeks ago, I over looked the work while the guy at the garage was servicing it. The garage advised me that I needed 8 spark plugs for the car so all of them along with a branded pollen filter, branded air filter,branded oil filter and top brand oil was all changed.

I have put brand NEW MICHELIN TYRES on they car all correct tyre pressure 30 psi on the back and 32 psi at the front but the MPG is still 25MPG on the trip meter, I have hit 30MPG on a round trip on highways but never get the type of MPG other members are stating, I read all the reviews on the net and all said it would do are 35/40 MPG inner city driving but I have never seen that.

I always keep to the speed limit, don't brake or accelerate hard, I don't have A/C on, the car does short and long range travel, I always fill up at Shell, but I am getting around 210 miles to a full tank which costs around £45.My boot is empty apart from the spare wheel which is a space saver that you get with the car. I really do not know what to do, I really thought that car needed a good service but that didn't work.

Does anyone have any ideas on what I can do to improve the MPG? I know the is a problem with the car but I don't know what it is, I have searched all off the internet but not come across a solution.

Thank you in advance for your replies.

Regards

 

I'm guessing that's 25 mpg imp, so 20 miles/USG? with the 1.4? Ouch!

I don't have anything really useful to offer, but welcome to the forum. Where in the UK are you? I spent some time over there in '05 and '06 - first place I saw the Jazz actually, along with all kinds of cool little hatchbacks (in the mid two-thous... mid oes.. mid-whatever-the-last-decade-was-called, hatchbacks had all but disappeared in the US.)

 

at what speed?

 

You need to disconnect the battery for a few minutes and reconnect the battery. It should erase the fuel trims and your car should run better. You will need the code to unlock the radio.

 

I'd say its the weight and hieght of the new Michelin tires/tyres, assuming of course that the service was done with the correct fluids, parts, and was performed properly.

Theoretically speaking, the tires are the only thing that would make sense in reducing your fuel economy since they are naturally heavier (if you kept the same tire/tyre size) than the previous tire due to the additional tread and would require more effort to move.

In addition to that, the vehicle's gearing very lowers slightly as the tires/tyres wear; which in turn would require *slightly less* throttle throttle input/engine effort to get the vehicle to the same speed as it would in the same vehicle with a new set of the exact same tires/tyres.

As for improving MPG, you just have to keep your momentum going. When approaching a light for example, staying on the throttle and braking at the last minute isn't going to help your MPGs as much as coasting (traffic permitted) to stop. Coasting would allow the throttle body to remained closed, reducing the amount of air and fuel going into the engine and allow the vehicle to slow by friction in its mechanical parts, tires, wind, and elevation change (if an upward grade).

Just my two cents by the way.