Fuel Consumption

[SAM LOVERS HER TOYOTAS]

Hi All,

Okay, so i filled my first full tank after recently having purchased my 2008 Aygo with 53k on her, completed a full service on her myself, tyres are brand new and at correct psi, no heavy loads what so ever, and filled up at Shell using their regular brand, admittedly i have a k&n panel air filter...and ive had 210 miles before my fuel indicator started flashing “R” this morning.

For a 3 cylinder engine and having read previous threads...210 miles is a bit pathetic or is it me expecting more, im sure i read other owners hitting up to 400 miles on local runs, or was i dreaming?

Appreciate any thoughts guys n girls.

Sammy

[Plob]

I generally get 330-350ish from a full tank on mine, but I often go way beyond the low fuel warning! My average consumption works out to 45mpg-ish.

I do however generally only go 10 Miles to work then home again in urban 30-40's, and I tend to drive quite hard... It's been said I could do with an on/off switch instead of an accelerator!!!! 😁

 

*edit*

40k, all standard, can't remember when I last checked oil or tyres!!! Boot and back seat full of crap!

Edited January 24, 2018 by Plob
Addition

[Cyker]

I'm getting ~350 miles to a tank on New Yaris (vs 600 on Old Yaris ) - Given the Aygo is lighter and running a 1.0 instead of a 1.33 I would have expected you'd get at least that...!

Are you driving everywhere in 2nd? 

 

I must admit I'm finding it tough adjusting to a petrol engine; Getting even close to the rated mpg is a crapload harder than it was in my old diesel Yaris!

 

[Wiz201]

I'm getting close to filling up and I've done 290 miles.

[SAM LOVERS HER TOYOTAS]

Thank you for taking the time to put forward your input guys,

some large numbers there...290 to 350...

If anything i do like to sit in 3rd during city driving because i feel thats wheres its all happening at...but will always fall into 4th when the roads and gaps in traffic permit.

I thought of something else that could be a factor...maybe a big one...we dont have a standard Aygo exhaust...its one in the middle...Toyota tte or t sport is it...could it be this that explains higher consumption and then the k&n panel filter coupled with it??? 

[SAM LOVERS HER TOYOTAS]

P.s i need to fill up tomorrow, im thinking if i should go to my local Morrisons rather than drive an extra 3 miles to get to my nearest Shell and pay more in fuel if 210 miles is all im going to get ???

[zuh]

210 seems abnormally low.

Of course, the exhaust might be the reason!

There can be many causes: condition of the road, level or hilly road, the way you drive and in the winter cold, consumption is a little higher.

Do you drive short or long journeys? At first, I worked 3 miles from home and my Aygo used more fuel than a sportscar, I was disappointed. Now I work 20 miles from home and the engine has plenty of time to heat so my consumption has dramatically gone down.

[Wiz201]

yep cars ultimately do better on longer journeys.

[SAM LOVERS HER TOYOTAS]

Hi

Well i filled a full one at Esso today, lets see how it goes, i average 15-20 miles a day all local, i recon its due to the exhaust that explains a higher fuel consumption.

[Planemo]

Sam, unless someone has stuffed potatoes up your tailpipe its not the exhaust.

Given that I have had, on several occasions, 420 miles with 2 bars still left I cannot for the life of me see how you would be less than halving this. Bear in mind I also have a sports exhaust.

Admittedly I usually average a bit less, plus I have a decat which I estimate gives me an extra 20 miles per tank, but 350 miles from a stock Aygo with a K&N and sports exhaust should be more than achievable. I usually get 385+ miles before hitting the last bar.

The last fuel bill I took note of gave me 432 miles between fills and took 34.84 litres. This equates to 61.6mpg. I dont think I have ever seen less than 50mpg.

Your 210 miles equates to 27.4 mpg which I cannot for the life of me see how you are achieving. I would not have thought that the Aygo could physically burn that much fuel in that distance. Was the gauge actually showing full after you filled up? The design of the Aygos filling tube can switch off the pump quite easily I find and lull you into thinking the tank is full. Perhaps your cat has become totally blocked? Does the car 'feel' strangled at all? (difficult to ascertain I know given the low stock power!) Exhaust smoke? There has to be a reason for this as no way is this normal.

[paulie b]

Hi Sam, 

I'm just filled my Aygo from half to full and it had done 190 miles. I too only do short journeys.

When I got the car the gauge was reading half full, but I ended up putting £40 worth of petrol in!  

 

Perhaps you could just travel 50 miles then fill the car back up (at the same Esso station) and that may give you a more accurate indication of you fuel usage?

[mickburkesnr]

2 hours ago, Planemo said:

Sam, unless someone has stuffed potatoes up your tailpipe its not the exhaust.

Given that I have had, on several occasions, 420 miles with 2 bars still left I cannot for the life of me see how you would be less than halving this. Bear in mind I also have a sports exhaust.

Admittedly I usually average a bit less, plus I have a decat which I estimate gives me an extra 20 miles per tank, but 350 miles from a stock Aygo with a K&N and sports exhaust should be more than achievable. I usually get 385+ miles before hitting the last bar.

The last fuel bill I took note of gave me 432 miles between fills and took 34.84 litres. This equates to 61.6mpg. I dont think I have ever seen less than 50mpg.

Your 210 miles equates to 27.4 mpg which I cannot for the life of me see how you are achieving. I would not have thought that the Aygo could physically burn that much fuel in that distance. Was the gauge actually showing full after you filled up? The design of the Aygos filling tube can switch off the pump quite easily I find and lull you into thinking the tank is full. Perhaps your cat has become totally blocked? Does the car 'feel' strangled at all? (difficult to ascertain I know given the low stock power!) Exhaust smoke? There has to be a reason for this as no way is this normal.

I have to agree with this. The most I ever got from mine was 530 miles, driving at 50mph down to Cornwall and back. On average though I do get about between 350 - 370 miles out of a full tank. I usually fill up at Sainsbury's, but once a month (or as close to it as I can get - I don't drive the car often these days) I'll fill it with V-Power and give it a blast down the dual carriageway to clear the injectors.

You mention driving in 3rd gear when in urban areas, I get to 4th as quick as I can as that's where the engine seems to cruise along at 30-40mph. Maybe your driving style could be an issue?

What sort of oil are you using? Are you using the 5w30 that these engines are specced to?

Have you changed the plugs during your service?

Have you washed the K&N filter?

[SAM LOVERS HER TOYOTAS]

5 hours ago, Planemo said:

Sam, unless someone has stuffed potatoes up your tailpipe its not the exhaust.

Given that I have had, on several occasions, 420 miles with 2 bars still left I cannot for the life of me see how you would be less than halving this. Bear in mind I also have a sports exhaust.

Admittedly I usually average a bit less, plus I have a decat which I estimate gives me an extra 20 miles per tank, but 350 miles from a stock Aygo with a K&N and sports exhaust should be more than achievable. I usually get 385+ miles before hitting the last bar.

The last fuel bill I took note of gave me 432 miles between fills and took 34.84 litres. This equates to 61.6mpg. I dont think I have ever seen less than 50mpg.

Your 210 miles equates to 27.4 mpg which I cannot for the life of me see how you are achieving. I would not have thought that the Aygo could physically burn that much fuel in that distance. Was the gauge actually showing full after you filled up? The design of the Aygos filling tube can switch off the pump quite easily I find and lull you into thinking the tank is full. Perhaps your cat has become totally blocked? Does the car 'feel' strangled at all? (difficult to ascertain I know given the low stock power!) Exhaust smoke? There has to be a reason for this as no way is this normal.

Planemo, i know this is shocking, coming to think of it when i purchased the car in December, i filled a full tank, drove the 120 miles home, and then my usual around town local runs, and i topped 450 miles or there abouts.

This last fill up was my second full tank since ownership where ive topped 210 miles, it makes me wonder what could have changed. My driving style certainly hasnt!

But hey, you’ve made me think...maybe my cat is blocked!!! Because YES it does feel strangled recently, and YES i do have what looks like excessive white smoke, but its not too bad, put it down to the weather. So what do you think, i need a new cat? Are they expensive? I dont mind changing it if it gives me 400 milers.

[SAM LOVERS HER TOYOTAS]

2 hours ago, mickburkesnr said:

I have to agree with this. The most I ever got from mine was 530 miles, driving at 50mph down to Cornwall and back. On average though I do get about between 350 - 370 miles out of a full tank. I usually fill up at Sainsbury's, but once a month (or as close to it as I can get - I don't drive the car often these days) I'll fill it with V-Power and give it a blast down the dual carriageway to clear the injectors.

You mention driving in 3rd gear when in urban areas, I get to 4th as quick as I can as that's where the engine seems to cruise along at 30-40mph. Maybe your driving style could be an issue?

What sort of oil are you using? Are you using the 5w30 that these engines are specced to?

Have you changed the plugs during your service?

Have you washed the K&N filter?

Hi, thank you for your input mickbukesnr,

530 miles...wow.

I dont think its my driving style, i enjoy 3rd but i change to 4th as soon as i can.

Just filled genuine Toyota oil 5W30 during my service a few weeks back, along with NEW sparkplugs, all genuine as all my parts were purchased from my Toyta dealer, infact i got my engine oil for free due their promotion.

The K&N panel filter is brand new out of the box too.

I recon as Planemo mentioned, it could be a blocked cat. I’m thinking whether i can unblock it somehow OR replace it myself.

[AYGOSTU]

I am on my 3rd Aygo, lowest mpg was 37mpg, I average 49 mostly.. 27 is impossible unless there is a problem ! 

[SAM LOVERS HER TOYOTAS]

3 hours ago, AYGOSTU said:

I am on my 3rd Aygo, lowest mpg was 37mpg, I average 49 mostly.. 27 is impossible unless there is a problem ! 

I understand that there must be a problem, hence i am asking what could be the problem? It doesnt make any sense, surely the recent cold spell couldnt explaint 210 miles on a full tank. My 15yr old just mentioned...could you have a fuel leak mum? My trainee mechanic son recons its either the cat or the fuel pump, can anybody tell me how i could test either of those please? I’d love to get to the bottom of this asap.

Is this another possibility...that we didnt torque the new spark plugs in properly...which is causing the Struggling issue that i mentioned earlier with our friend Planemo?

[AYGOSTU]

Good luck diagnosing, I really hope you get to the bottom of it. Fingers crossed it’s an easy fix

[Micra2Aygo]

Could your son not borrow a code reader and see if there is a code to read?  Even using an app like Torque will be able to read any codes and also monitor what the O2 sensors are saying. 

I've been using Torque to monitor my Aygo's fuel trims and O2 sensors to help me with a occasional knocking i get on acceleration from standstill. Its a long story but basically my fuel trims were slightly negative which meant the car was adding slightly less fuel that what the base map wished.  The post cat O2 sensor was a bit high as well.

Added some Redex which initially helped but the next redex free tank things went back to almost where I started. Tried some Millers Ecomax next over the 2 tankfulls, and now I'm near the end of the 1st additive free tank and the fuel trims are much better as is the post cat O2 sensor reading.  I'll do another additive free tankfull and see where things go.

As for MPG, I do a 20 mile or so commute mainly on dual carriageways doing 70 to 75 (75 on the speedo = 70 on GPS)  and I get 51 to 53 MPG   with 53 to 56 in the summer.  If you can see what your O2 sensors and also what the MAP and vaccuum sensors are saying then you may get some clues.

Finally thought, does the engine get up to temperature?  A dodgy thermostat would give low MPG as the car would always run rich.    

[Planemo]

Fuel pumps run at max pressure at all times, so any faults with them will nearly always reduce pressure, not increase it. I think it highly unlikely that an issue with the pump will be the cause.

Excess fuel from the pump is returned to the tank by the fuel pressure regulator so if there is an issue with the regulator it *could* potentially supply too much fuel to the injectors but again this is highly unlikely as regulators will again usually supply too little when they play up rather than too much.

Catalysts are not user-repairable. You could (as I have) remove the cat and take the guts out of it but this will cause problems come MOT time. If you suspect a blocked/broken cat, the cheapest and easiest option is to buy a used one off eBay and try it. I found they go for around £50 or so. If you do want to remove the catalyst core, you need to cut open the manifold to get to the core. The opening you made will then require welding to plate it up again.

Fuels leaks do not usually go un-noticed for long due to the obvious whiff of the stuff. No harm in running the car on idle and poking your head around/under the car to see if you can see/smell anything though. If the issue you have is down to a leak then you will undoubtably notice it because respectively speaking, we are talking about quite a lot of fuel.

Your spark plug would pretty much have to be out in order to reduce the power to such an extent that you were heavier on the throttle to compensate for the power loss. You would also know if it was only running on two cylinders because with only 3 to start with it would run like an utter dog. Even a loose plug would not cause a fuelling problem this bad, unless it was so far out of the hole that it wasn't igniting the mixture but again you would certainly hear it blowing and/or the engine would run like a Briggs and Stratton lawnmower.

Buying an OBD port reader and trying Torque as suggested is a good shout as it's cheap to do. I am a firm advocate of Torque but primarily find it good for monitoring rather than actual diagnostics. This is because the OBD system on the Aygo is not exactly comprehensive compared to later vehicles. As has been said though, it will be possible to see what the coolant temp is and also see the O2 output but I found the lambda readings to be a bit iffy tbh. However, with a fuelling issue as bad as we are suspecting, I would think that any issues with resolution from the sensors/Torque app would prove insignificant in the scheme of things so it could be worth a go.

Bear in mind that *if* the problem is down to excess fuel being sent to the cylinders (and not a leak), it is highly likely that your cat will now be kaput from the horrendously rich mixture. I am surprised that you don't have an ECU light on tbh, as I would have thought that the O2 sensor would throw up a fault code in such a circumstance but like I said, the ECU system on the Aygo is fairly simplistic and basic.

The easiest way to accurately check O2 levels would be to take it to a tuning shop with a rolling road, hook up a wide band lambda to the tailpipe and do a power run. This would bypass all the info coming from the stock o2/ECU and tell you in an instant if its running rich. Wide band lambdas are incredibly accurate and being able to check fuelling throughout the rpm/load range would rule out any red herrings that may/may not decide to present themselves at certain points in the fuel map/fuel pressure. The stock o2 sensors (both narrow band) are only really of any worth at idle and extremely low load conditions. And they don't even do that very well tbh.

Also, a power run would do exactly that - check your power.

After that, diagnosis could start but it wouldn't take long to do under these circumstances because your raw data would be excellent. A blocked cat would seriously affect power. A sudden rise in fuelling at say 3000rpm could be a faulty injector/regulator. A fuel leak that only presents itself under high rpm would be identified. Etc etc.

Sorry to go on but the above is just stuff that I am thinking out loud on as I type.

 

[SAM LOVERS HER TOYOTAS]

Wow Planemo and Micra2Aygo...loads of technical informartion there, much appreciated, i shall investigate as many of those factors as i possibly can and report back shortly, cheers guys.

[SAM LOVERS HER TOYOTAS]

Morning All,

Quick update, woke up very early this morning to work on my baby. Time is limited when running your own business!

Anyhoo, ok, so i removed my spark plugs, gaps spot on, and torqued spot on, no evidence of anything untoward on each plug btw.

Next, i sprayed some Wynns carb cleaner with the throttle open, not an easy job guys, the engine revs so much before you have a clearance space at the opening to even get a thin straw in! Spayed a few squirts only before i gave up...intended to finish the can on the job...i could hear the engine sound change as i sprayed...seemed a little better...BUT THE BLACK SMOKE SHOOTING OUT THE BACK...WOW...so what does that tell us...the black smoke?

Please help.

Took it round the block a few times in 2nd driving like a maniac...seems to have alot more poke.

Im thinking a bottle of Cataclean next? There is a strange sound coming frim the exhaust...unsure if its normal...not so much a blow but a bit of a roar...saying that its one of them TTE boxes...i still wonder if it is the cat?

After the Cataclean its a trip to the garage to plug in their diagnostics.

[fordulike]

Sorry for hijacking the thread a bit, but do the catalytic/lambda sensor type cleaners actually work? Fancy popping something in the tank soon (32k), can anyone recommend a cleaner please.

[mickburkesnr]

On 1/28/2018 at 11:33 AM, SAM LOVERS HER TOYOTAS said:

Next, i sprayed some Wynns carb cleaner with the throttle open, not an easy job guys, the engine revs so much before you have a clearance space at the opening to even get a thin straw in! Spayed a few squirts only before i gave up...intended to finish the can on the job...i could hear the engine sound change as i sprayed...seemed a little better...BUT THE BLACK SMOKE SHOOTING OUT THE BACK...WOW...so what does that tell us...the black smoke?

Please help.

Took it round the block a few times in 2nd driving like a maniac...seems to have alot more poke.

Im thinking a bottle of Cataclean next? There is a strange sound coming frim the exhaust...unsure if its normal...not so much a blow but a bit of a roar...saying that its one of them TTE boxes...i still wonder if it is the cat?

After the Cataclean its a trip to the garage to plug in their diagnostics.

Fairly normal really I would say, in terms of black smoke. I put half a car in my Corolla then started it, lots of smoke came out the back! It's a mixture of the chemicals being ignited, the deposits it's removed from the combustion process. 

I wouldn't touch the catalytic converter until you run the diagnostics on it using an OBD2 reader. If your cat is having problems then you could very well find that the O2 sensor will be giving errors. This usually manifests itself as an engine management light, but you've made no mention of it being on I don't think. As it's second hand, the bulb may have blown or been removed (it does happen). The OBD2 reader will tell you if there's any error codes which would trigger the EML. 

As for Catalytic convertor cleaners, I don't think they'll do a whole lot. By their very design the converters run at very high temperatures so I wouldn't imagine any soot blocking up that much to clog it up. Plus I would think that chemicals extra to the usual petrol combustion produced products may even 

However, that said, you could have an Aygo with a 3rd party catalytic converter. I used one myself, the car's performance suffered. It wasn't until I replaced it with a second hand unit from a Peugeot did it make a noticeable improvement to the response of the engine. You'll know if you have a 3rd party job from Euro Car Parts as it'll look like something welded together by some blind one handed chimp in a shed with no light.

Changing the cat is simple enough. Front bumper comes off, bolts off the engine and the down pipe. You'll need new gaskets from Toyota, they're about £10 for the manifold and £6 for the down pipe.

[Cyker]

It could be all this complicated stuff, but then again maybe you just need to rag the **** out of it on a fun hoon along some country lanes and fast hilly A-roads!

I used to think it was just diesels that get gucked up from being driven too gently, but apparently modern petrols get affected by the same things if they're driven lightly all the time, esp. if they have EGRs, so take it on a fun hoon and get the engine good and hot and that should burn off any crap on the injectors and exhaust!

I only mention this as I had to do a 3rd gear 5000rpm overtake up a really steep hill today (I bet my Mk1 D4D could have done that in 5th...) and the engine feels slightly more free running now (And also I now need to refuel the car tomorrow...)

But the good ol' 'Italian Tune-up' works wonders on cars that haven't seen anything north of 3000rpm for years!

 

[zuh]

6 hours ago, Cyker said:

I only mention this as I had to do a 3rd gear 5000rpm overtake up a really steep hill today (I bet my Mk1 D4D could have done that in 5th...) and the engine feels slightly more free running now (And also I now need to refuel the car tomorrow...)

I confirm :)

After a long journey on the highway at high revs, the engine feels different. I try to do it regularly.