Yaris Mpg

[mojo7676]

hi. i've been driving an 04 1.0vvti petrol yaris for couple of months - car as about 35 k miles and seems to run okay. trouble is it only does around 30mpg - brim to brim. i do mostly local journeys but it still seems low to me, i changed the p-lugs from platinum to normal ones - changed filters n oil and that but still the same. is there anything i'm missing? no engine codes but will putting it on a scanner show anything?

any advice appreciated

mojo7676

[stantheman1]

Do not be unduly worried as you have chosen a bad time to evaluate the frugalness of the Yaris or any other car for that matter, the trouble is short journeys coupled with extremely cold weather equates to low mpg.Things should improve greatly once the warmer weather arrives or you go on longer runs taking in less than congested 'A' roads and Motorways.

[Johan007]

Cold engines are really bad for MPG though cold air is really good for MPG in petrol cars. So 30 MPG sounds too low because I can't get lower than 38mpg in my 1.5 T-Sport. Presume you have checked air filter and run regular petrol? Presume you have also manual calculated mpg though my trip computer is spot on. This is a good tool for anyone to calculate mpg: http://www.fuel-economy.co.uk/calc.shtml

[mojo7676]

thanks for the replies

i understand that colder weather etc can impact mpg; but my other car - 1.8 vvti celica is still returning around 30mpg.

i am using unleaded and have worked out mpg manually (miles travelled divided by number of gallons used (litres divided by 4.54)). last time i filled up it cost just under 40 quid for about 220 miles. worse still, i've been driving very very light footed. one thing i have noticed is that it does take a good five minutes to warm up - double the time it takes the celica to warm up.

thanks anyway - will report back if anything definitive comes up

mojo7676

[stantheman1]

Mpg can greatly improve if the car is garaged overnight when frost is due, if you're anything like my other half who has to scrape ice off the windscreen before doing the school run in the morning then I'm not suprised by the low return(has the engine running whilst de-icing). The wife's 1.0 ltr Yaris does about 30 mpg in those conditions and in the warmer months manages around 39 mpg for the same journey and if we use her car to go further a-field then 55 mpg is not unheard of, regardless of the weather.

[Raeman]

hi. i've been driving an 04 1.0vvti petrol yaris for couple of months - car as about 35 k miles and seems to run okay. trouble is it only does around 30mpg - brim to brim. i do mostly local journeys but it still seems low to me, i changed the p-lugs from platinum to normal ones - changed filters n oil and that but still the same. is there anything i'm missing? no engine codes but will putting it on a scanner show anything?

any advice appreciated

mojo7676

You may have just answered your own question there. Small runs, heaters, wipers, heated rear screen, lights will all zap the fuel and it's the same for us all in this awfull weather.

I had a journey today of about 15miles and the best MPG i got was 37. Without everything switched on, i can easy get 46mpg doing the same journey at the same speed.

Another thing is make sure the car is well maintained and the tyres are correctly inflated.

[mojo7676]

okay - thanks for that and while i do understand that low temps and high loads can adversely impact economy, the extent of the impact has never been so heavy in my experience. i know i'm working with a theoretical (as opposed to an actual) baseline of around 40mpg. but like i said, the celica dioesn't seem to be as significantly effected as the yaris. also, the yaris has cnosistently returned what i think is poor mpg; even before the really cold weather. engine seems to run okay, all tyres and pressures fine also - may get it checked to see if running rich as a starting point

[Madasafish]

Check for binding brakes

Air filter dirty...

[mojo7676]

Check for binding brakes

Air filter dirty...

thanks for the tips: changed air filter with plugs; brakes not binding (checked when replaced front tyres).

[Vitz_man]

Sounds to me like something still wrong though if your average is that low. Im up around the low 40's with the same (but older) engine. Normally im high 50's to low 60's (on a good day - even had it up to 67 at one point, no idea how though!) so you might want to seek professional advice if your cars returning that sort of economy.

Checked your wheel alignment? If its really bad or you're "crabbing" that could theoretically affect your fuel economy.

[mojo7676]

Sounds to me like something still wrong though if your average is that low. Im up around the low 40's with the same (but older) engine. Normally im high 50's to low 60's (on a good day - even had it up to 67 at one point, no idea how though!) so you might want to seek professional advice if your cars returning that sort of economy.

Checked your wheel alignment? If its really bad or you're "crabbing" that could theoretically affect your fuel economy.

have checked tyres and they seem okay; the old ones were getting close to limit when changed over a month ago but the wear was even. back two tyres seem fine. may get them checked proper, though

thanks

mojo

[Cyker]

How prone are the petrol Yarissseses to getting injector clog?

I tend to drive my diesel one around at barely above idle most of the time, and found it was loosing 'pull' over time, and consequently needed use the accelerator more to make it go, which obviously affected the mpg.

Apparently my low-rev driving was allowing crud to build up on the injectors, so now I stretch it now and then, and drop a tank of V-Power in every now and then and it seems to help.

[mojo7676]

How prone are the petrol Yarissseses to getting injector clog?

I tend to drive my diesel one around at barely above idle most of the time, and found it was loosing 'pull' over time, and consequently needed use the accelerator more to make it go, which obviously affected the mpg.

Apparently my low-rev driving was allowing crud to build up on the injectors, so now I stretch it now and then, and drop a tank of V-Power in every now and then and it seems to help.

thanks for that but not sure how relevant injector clog is with petrol engines - had the same issues you describe with a vw and merc diesels in the past but never petrol. that said, this yaris was a bit hesitant when setting off and needed heavy footing; but that was 'cured' with new set of plugs (previsouly running with some fancy dan platinum plugs, i noticed - not original spec according to the folks at toyota). might run some injector cleaner through it but i don;t think theres a problem because everything seems to run more or less fine.

onward and all that

mojo

[alfiejts]

Different cars do naturally have different results - just down to the build tolerences of the engine, age affecting some of the engine management sensors differently, tyres, etc.

Different tyres can easily make a 10% difference too and that's 4mpg on a Yaris....

Over the 193 tankfuls put into my 1.0 over 8 years, they were all in the range 38 - 48 MPG and the overall average over 64000 miles was 44mpg.

Car was garaged overnight and most of that was local town driving.

(and 23 tankfulls in our 1.3 have varied from 35-41mpg, averaging 38mpg - but the daily commute is a lot more "stop start" than it was when we had the 1.0 Yaris, so the results will be worse anyway)

[mojo7676]

thanks for all the comments and input; some very useful context and benchmarks.

anyway, bit of an update

had the car emission checked - a mech friend told me it would help point to something concrete like a lambda sensor. and guess what? everything's fine - all readings are as they ought to be, more or less.

so - next stage is to run it on a tank full of the good stuff while also getting tracking/tyres rechecked. don;t know if it'll make any difference but it's worth a shot

thanks again

mojo

[mojo7676]

update since last top up. not much change, really

cost me 41.50

115.9 per litre (Shell v stuff)

= 35.8 litres

divided by 4.54

= 7.89 galls

distance covered - 255 miles

255/7.89 = 32.3 mpg of very light footed driving

i'll see what happens with the v power stuff and report back if anyone's interested

mojo

thanks for all the comments and input; some very useful context and benchmarks.

anyway, bit of an update

had the car emission checked - a mech friend told me it would help point to something concrete like a lambda sensor. and guess what? everything's fine - all readings are as they ought to be, more or less.

so - next stage is to run it on a tank full of the good stuff while also getting tracking/tyres rechecked. don;t know if it'll make any difference but it's worth a shot

thanks again

mojo

[carlowlad]

Always interested when it comes to mpg topics!

[Madasafish]

DIESELS RULE OK!

57mpg average..

:-)

[alfiejts]

DIESELS RULE OK!

57mpg average..

:-)

Well I sort of fully agree.

My own car is a diesel Audi and its great - but when we were looking to swap our old Yaris, I worked out that even with the better economy of the diesel version, with the extra purchase cost and the extra cost of diesel fuel, it would take until the car had done 60,000 miles (which is 8 years for us) before the economy savings balanced out and started to exceed the extra initial costs.

I was happy to buy either, as the "total cost of ownership" of both cars would be almost exactly the same at the sort of mileage and age we would expect to sell the car on, but after driving both diesel and petrol Yarii, my wife preferred the driving characteristics of the non-turbo 1.3 petrol engine - so that's what we bought...

At the time we bought, we would have had to pay £1700 more to buy the same car as a diesel and that's a lot of extra money to recoup even with the better economy.

Not trying to push anyone either way - I think both petrol and diesel Yarii are great - just try both out and make a purchase decision on all the factors not just the "headline" mpg figure.

[mojo7676]

tell me about it - my wife's 2.0 audi a3 does 40mpg plus around town, similar sort of driving cycles, too. as i said in a previous post, my celica vvti wasn't far off the figures for this yaris.

just had tracking done so see if that makes a difference; it wasn't out by much according to the mech. i still think there's something amiss with the yaris - just don;t know what... yet

mojo

DIESELS RULE OK!

57mpg average..

:-)

[Madasafish]

just had tracking done so see if that makes a difference; it wasn't out by much according to the mech. i still think there's something amiss with the yaris - just don;t know what... yet

mojo

Further pointers:

check engine temperature warmup..

Does it take a long time for the green light to go out?

Check the coolant temperature sensor? May be it is faulty?

If the car has only averaged 6k miles a year, chances are the air inlet is filthy... there are lots of articles on cleaning these.

I think you have checked the MAF sensor?

Is the engine oil 5-30W? Anything heavier will reduce mpg.

Mu guess is car has been driven lightly and is coked up...,

[Raeman]

Have you checked the brakes for any binding?

If they are ok, i would suggest giving it a good long M/Way run, occasionally revving it high.

As Madasafish says, it could just be coked up, maybe even try some redex or injection cleaner.

[mojo7676]

thanks for the tips

will change oil in case was running on something different -

engine takes maybe 5 mins to warm up/green light to go out

don;t know how to check coolant temp sensor - any pointers appreciated

haven't checked air inlet (air filter was changed a month ago with plugs) - will search for 'how tos' - but links appreciated

haven't checked maf either as the running seems fine - doesn't cut out or anything, though i have to say sometimes it does become unresponsive-ish when setting off gently to the extent that i have to raise revs just in case it stalls (which it does on occasion when setting off). when checking maf, i imagine it's a physical inspection - any tell tale signs?

the car's only done 30ish thousand miles so yes, probably been tootling around more than anyting else

thanks again - will endeavour to mess around over the weekend and report back any findings

mojo

Further pointers:

check engine temperature warmup..

Does it take a long time for the green light to go out?

Check the coolant temperature sensor? May be it is faulty?

If the car has only averaged 6k miles a year, chances are the air inlet is filthy... there are lots of articles on cleaning these.

I think you have checked the MAF sensor?

Is the engine oil 5-30W? Anything heavier will reduce mpg.

Mu guess is car has been driven lightly and is coked up...,

[mojo7676]

thanks for that - topped up with prmium type fuel and used some lucas additive/cleaner stuff a while ago but made no difference; might shove some more in

will also knock the crap out of it when i next gfet the chance. sick of driving this thing like it's made of china

in the meantime, been searching for 'air inlet yaris' but can't find any topics/how tos - what am i missing?

thanks

mojo

Have you checked the brakes for any binding?

If they are ok, i would suggest giving it a good long M/Way run, occasionally revving it high.

As Madasafish says, it could just be coked up, maybe even try some redex or injection cleaner.

[mojo7676]

and another update, if anyone's bothered

topped up - last time with Shell v power.

new data since last fill:

travelled: 291 miles (60 miles of which was motorway driving, mostly at a steady 50 because of roadworks/speed cameras!).

cost to brim up: £41.75 @ £108.9 litre = 8.44 gallons, approx

291 miles divieded by 8.44 gallons = 34ish mpg.

pretty much no difference, i'd say - previous figures were around 32 mpg but all local/urban driving; this new figure, as i say above, includes about 60 miles at pretty tame and steady mway driving.

so, to that end: might be time for a change as i'm getting pretty disappointed in this car, so far - apart from the relatively lousy mpg, there's this weird and inconsistent squeaking with the clutch pedal; every time i dip the clutch, it creaks! however, it onlty does this some of the time!

With reference to the economy issue, i may just get it hooked up to a reader in case something is not showing on the dash. not had a look at the maf thingy because it seems a bit challenging and also because i've been told it either works or it doesn't; and if doesn't work, some engine management light comes on.

anyway, onwards and all that

thanks for all the tips -

mojo

hi. i've been driving an 04 1.0vvti petrol yaris for couple of months - car as about 35 k miles and seems to run okay. trouble is it only does around 30mpg - brim to brim. i do mostly local journeys but it still seems low to me, i changed the p-lugs from platinum to normal ones - changed filters n oil and that but still the same. is there anything i'm missing? no engine codes but will putting it on a scanner show anything?

any advice appreciated

mojo7676