01 1.3 what is causing my poor fuel economy? - polecat10
Hi,

I have a 1.3 16v suzuki wagon R on a Y plate.
The handbook says I should get between 36(urban) and 55(extra-urban) MPG but the most I have managed on a longish run at 65mph is 38mpg, and in mixed driving I get around 34mpg. Owners on suzuki forum report 45mpg is easily achievable.

I've changed the plugs, oil, air filter and oil filters to no avail- and the tyre pressures are spot on. The car has only done 45,000 miles and has been serviced each year from new, any ideas what the problem could be?

I know I am calculating the mpg accurately so am a bit stumped.

I'll be very grateful for any ideas you might have.

Cheers,

Mike.
01 1.3 what is causing my poor fuel economy? - madf
Relatively low mileage so I suggest an Italian tuneup first.

(Search the forum if you don't know what it is)
01 1.3 what is causing my poor fuel economy? - polecat10
Relatively low mileage so I suggest an Italian tuneup first.

I think I've heard this term before- does it really work? Got to be worth a try so I plan to add a fuel additive/cleaner then take it on a long run on Saturday- what do I do to get the best results? is there a trick to it? High revs? or just a long run at high speed? or keep flooring it then slowing or what? How long do I need to be at high revs/speed for?

Cheers,
Mike.

p.s.
Just spoke to a mechanic (it was in for new front discs this afternoon) and he couldn't suggest anything except taking it to suzuki to look at the engine management- although no engine lights have been on and it runs smooth.

01 1.3 what is causing my poor fuel economy? - Lud
polecat: to do an Italian tune-up, with or without fuel system cleaner additive, go for a long drive. When the engine is thoroughly warm - after say half an hour - let it run, without wringing its neck, to higher engine speeds than usual. No need to redline it but get up towards that region. Do it a few times, in the intermediate gears, at conservative throttle openings, repeatedly over a couple of days perhaps, always making sure that the engine is properly warm first.

If the engine has become a bit fluffy owing to many short, slow urban trips, this technique may make it feel quite a lot livelier. It goes without saying that filters, plugs and oil should be in good condition.

It may not happen so much with modern cars, but in the past I have broken the top piston ring in one cylinder (that's all it takes) by revving the nuts off cars used to being driven at lower, constant rpm. You have been warned.
01 1.3 what is causing my poor fuel economy? - polecat10
Thanks,
I'll give it a blast after work tomorrow, also going for a 50 mile run on Saturday.

I've had it 6 months and driven it like a bat out of hell quite often but never for more than 30 minutes and only short trips. (we use the ford puma for longer runs)

I'll let you know if I see any improvement.

Mike.
01 1.3 what is causing my poor fuel economy? - TurboD
Doubt it will work. Some cars just do not reach the mpg of others, I know I have tried this lark before.
The most important feature is the Driver!. My wife can get 5 or more mpg out of our cars than me, I am too heavy footed, brake too much etc. Have you got any one else that drives the car?, do they get more?
Unless the timing is out, hole in the tank, binding brakes ,it is often the driver that makes the problems- ( do you have a boot full of junk, flat tyres?)
01 1.3 what is causing my poor fuel economy? - polecat10
Achieved 42MPG at the weekend!- a record but still a long way off the 55MPG quoted in handbook and 50+MPG achieved by others -and the 45MPG my 1.7 ford puma gets when driven similarly.


-added a fuel cleaner to previous 1/4 tank and drove at high revs for 10 miles after engine warmed.
-trip was almost all on major roads and kept to 60-70 mph. accelerated sensibly.
-tyre pressures are at upper end of limits.(between figures for unladen and fully laden)
-air filter, oil & filter & plugs are new.
-new pads and discs on front.
-windows closed and no luggage- just one slim passenger.
-car has done 50k and been serviced yearly.
-no air con.

only one thing- handbook recommends 10w30 engine oil but autoparts only had (and recommended) 5w30 when I did the oil change- could this have a big effect on fuel economy?

Thanks,
Mike.
01 1.3 what is causing my poor fuel economy? - jc2
If anything,the thinner oil should help.
01 1.3 what is causing my poor fuel economy? - Woodspeed
The figures in the handbook are government figures, and no owner will achieve them. The urban figure is about correct for overall driving.
5/30 oil is slightly thinner when cold than a 10/30 but hot (normal running) is the same. You can also get a 0/30 (great if you live in the arctic circle or a cold country that you have to start the cold at below -15C. It will still be the same hot.
01 1.3 what is causing my poor fuel economy? - Rob E
Hi,

It sounds as though your fuel economy is probably about right. Do bear in mind your car is a 2000/ 2001 model, so for a car of this age to get anywhere near the official figures (achieved in optimum and highly unrealistic conditions) is unlikely. The aerodynamics of the Wagon R don't help it, and if it's windy fuel economy will dip.

Note also that an Italian tune up is not the best way to maximise economy - it's all about smooth and gentle! The aerodynamics of the Wagon R mean that at motorway speeds there will be a lot of wind resistance, so this will also impact on economy.

I blew the Oxygen sensor on a 1995 Suzuki Swift while doing an Italian tune up (and holding it in 3rd at 70mph for far too long... ooops!). Learnt from that experience, and now believe that enthusiastic acceleration does just as good a job (provided the engine is properly warmed up first).

Hope this helps,

Rob.
01 1.3 what is causing my poor fuel economy? - SpamCan61 {P}
I'd be tempted to try a 55mph cruise for a while, with a fairly small engine and not exactly slippery shape I would think the economy of a Wagon R drops off very quickly with increasing speed.

Maybe I'm weird but I can actually achieve the official extra urban figure for my lovely green Vectra ( 1999 2 litre, 159K) by driving at 55 - 60 on the motorway.

I suppose there is a chance that the engine is being slightly over fuelled, maybe an auto electrician with the right code reader could check the fuel trim levels, assuming this is actually possible on this vehicle.
01 1.3 what is causing my poor fuel economy? - MVP
Try using some good quality fuel - the additives may help clean out the engine, unstick valves etc

Shell, BP and Texaco I believe are the best - avoid stuff from supermarkets

MVP
01 1.3 what is causing my poor fuel economy? - Dynamic Dave
Shell BP and Texaco I believe are the best - avoid stuff from supermarkets


My car (2.2 Vectra-C) gets supermarket petrol 99% of the time. Sometimes Tesco, sometimes Sainsburys. Never yet missed a beat.

BP fuel better than supermarket petrol? Now I wonder who supplies Sainsbury's with their fuel. Oh yes, BP ;o)

www.petrolprices.com/sainsburys.html


Edited by Dynamic Dave on 19/03/2009 at 18:34

01 1.3 what is causing my poor fuel economy? - MVP
www.honestjohn.co.uk/faq/faq.htm?id=46
01 1.3 what is causing my poor fuel economy? - polecat10
Okay- I'm relieved... (you've put my mind at rest that the engine doesn't have a major problem)
...and disapointed that I'll have to put up with 35-40mpg.
I'm driving to to France over Easter (1,200 mile round trip) and will do a flat section(at least 150 miles) at 55mph to see if i can get an improvement on the 42mpg record so far.
Will post the results on here.

Thanks to everybody who responded!
Mike.
01 1.3 what is causing my poor fuel economy? - polecat10
did a 1500 mile trip to Brittany from NE England last week.
Achieved 45mpg on one stretch- this was driving at around 60mph.
 

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