calnon: @ seina, you write up educated us a lot, because we don't take congnisance of those things like tires can cause increase in fuel consumption. My problem is my car doesn't move very well, expecially when clinbing a heal and it consume fuel too.

tmeeto: I used to drive a Toyota yaris wich was vry economical on fuel,I recently changed to a 2008 Hyundai elantra wich I believed was also fuel efficient but d way d Elantra consumes fuel is alarming compare to the yaris. Is dis normal o?

Gelatoman: Hello Siena,


Your contribution in the forum is priceless.

I drive Toyota Avensis 2005. After 6months of using this car i suddenly noticed that it consumes fuel more than Vampire consume blood. I have serviced the injector and nozzle. The silencer does not emit black smoke. My mechanic said the catalyst has been removed which is the cause. I argued this with him cause I only noticed this after six month and the car has never slept in mechanic workshop for a day. What do you suggest?

Also, 3 of my tires are 195/65 and the 4th one is 205/60....can this also cause high fuel consumption?

oh bruv , i use the Avensis 2004 t spirit , its the catalyst coverter that is the cause of your issue , especially if the engine management light has come on on the dash board , basically toyota told me that these cars have 4 OXYGEN sensors on the catalyst coverter , if one has malfuncton the em Ight comes , pls note that the car will drive well but the fuel consumption will start to rise , basically the whole catalyst converters need to be changed if you want low fuel consumption , if you dont want to change the catalyst converter ..then drive below 70 miles an hour .....Many thanks

JaaizTech:
Yeah your engine may be old, but if it is not smoking yet i think you can still benefit from a general tune up. Try this:
1) locate your air filter and if dirty replace it with a new one
2) Check your plugs and replace them if necessary with recommended specs.
3) Replace your plug wires if you have never before.
4) since your car is so old, and you are using injectors, servicing the injwctors can only be good.
5) lastly check your exhaust, they all get clogged over time.

Siena:
Things that can make a car thirstier than normal:

01) Dirty / clogged air filter.
02) Incorrect ignition timing. *
03) Under-inflated tyres (higher rolling resistance).
04) Binding brakes.
05) Leaking fuel injectors.
06) Blowing exhaust system.
07) Faulty MAF (mass air flow meter).*
08) Faulty CTS (coolant temperature switch).*
08) Faulty o2 sensor (Lambda).*
09) Thermostat stuck open, or removed by some dodgy mechanic. Over cooled engine.
10) Split / perished vacuum hoses, engine drawing in unmetered air.*

I would suggest an OBD scan, your '03 Honda Accord is fully OBD II compliant. All the items marked with an asterisk will normally trigger an engine check light (CEL). It would help too, if you can recall when you noticed the higher than normal fuel consumption. Did it occur after any work was carried out on the car? The thermostat is an area I would look into - if it's stuck open (or it's been removed) the engine will never reach its optimum operating temperature. The CTS will sense the engine is not hot, and the ECU will send more fuel through the injectors as a result. This is done by altering the duty cycle (the amount of time the injectors are held open will be longer).

Tyre pressures are also important, if the pressures are too low, the rolling resistance will place more load on the transmission, then the engine will work harder. The same goes for brakes that are binding (sticking on).

pak:
Thanks you'all, the problems have since been solved.
For posterity, they were :
1. Using bigger tyres than the recommended size, as stated below
2. My Mechs put water inside the radiator instead of coolant after servicing, leading to the engine operating at a higher temperature than normal.
Good thing is the car is still on the road, still ran around town with it today.

yhemisog:
I experienced exactly almost same wiv ma EOD 03 too, a friend adviced i change d exhaust, and on getting 2 my panel we discovered d catalyst had burnt or probably not even there at all . This was exactly what caused the outrageous fuel consumption. The guy opened it up and added some iron netlike kit inside it. Lo nd behold the consumption stop instantly. Try this bro it mite work 4u. My car is sound now , i nor dey sweat inside a.c. again d fuel consumption almost give me stroke.

kormene:
This is a nic thread cus this low millage issue aka high fuel consumption eats me up n I thank God n u guys for really dissecting the issue.
I drive a CRV 02 as my 1st car n must confess d car is a BOMB!
Don't get me wrong I mean d car is great n indeed a good buy especially in terms of engine performance.
The issue am having now is that due to bad road and ageing, am spending more now to replace parts.
One of which is what I've learnt from this forum. I think my catalytic con, air filter needs replacement n maybe my injector needs servicing. I think I also have unmetered air flowing into d engine tru broken air pipes which I'll change or seal cus like I said b4 my fuel consumption has gone up d roof.
Once again I say thanks guys

victorazy:

And you omitted Weak Engine Oil! What kind of Mechanical Engineer u be sef? Don't you know that weak or bad oil can stiff the engine which will make it to consume fuel cuz is struggling to work?

Siena:


An old post, but I'll respond anyway.

There is no such thing as "weak engine oil". Is there "strong engine oil" as a polar opposite then? Common sense will alert YOU if the oil viscosity has broken down. Way before the crank and cams begin to bind, the oil pressure warning light will be illuminated, and the hydraulic lifters (as applicable) will be rattling loud enough to wake the dead. If you ignore these warnings, then you don't deserve to own a car, and shouldn't even be trusted with a wheel barrow.

What kind of "end user" are you anyway? Your analogy, question and manner of expressing yourself makes you come across as thick, ignorant and very, very uneducated.

victorazy:


GILBBERISH!
You filled my space yet you couldn't make any point.

See this man is telling me there is nothing like weak engine oil. Why do u change ur oil? What do we call oil that has lost its texture.

Go and study more because u lack decorum.
"if the oil viscosity has broken down." when something breakdown, will it still active or weak? Speaking what u don't know.

Your explanation still lacks empirical thesis.

You must be a yoruba boy.

Things that makes car consume more fuel:
1.Oil with broken viscosity
2. Tyre alignment
3. Tire gauge
4. Bag plugs which causes improper combustion
Etc oc

Siena:


You are acting like a typical automobile end-user, who's been given snow jobs by a series of "mechanics" all his life.

Read the title of this thread carefully - "What causes a car to start consuming fuel excessively?"

Now if you weren't in such a mad rush attempting to discredit the points I raised, you would realise there are several factors, more than enough to fight fill 3 A4 sheets of paper.

I listed the most obvious. You citing "weak engine oil" is the daftest cause anyone could hope to list. No one with an iota of automotive know-how would describe degraded oil as "weak oil." The oil is said to have degraded, or its viscosity has broken down.

You're one of the same people who would describe a faulty ECU as "the brain box is weak." If oil viscosity had broken down to the point of the engine seizing, there would be more obvious warning signs - oil pressure warning lamp illuminated, rattling hydraulic lifters, a reluctance for the engine to rev, massive lack of power etc.

Did the thread starter mention any of the above symptoms? He was happy with the advise I was able to give whilst NOT being in charge of his vehicle, and 4 years on, he's probably sorted his car out. Why make it your business to criticise my suggestions? Instead, you should have given YOUR own suggestions, and left it at that!

And of course, people of your ilk will resort to tribalist remarks, which is enough to earn you a lengthy ban. Just so you're aware, I'm not Yoruba, nor any of the "major" Nigerian tribes. I'm what the rest of the world sees, a NIGERIAN. Though what has being Yoruba, or not, got to do with anything being discussed on an Automotive thread?

You discredit yourself, and everything you stand for with the emphasised portion of your post, that shows as nothing else can, that you're a tribalist, with nothing useful to contribute to these boards. Try making tribalist remarks in Politics section, they MAY be accepted there, but somehow I doubt it.