2012 Yaris 1.4D getting 33 mpg ~ 7 L/100km. What could be wrong?

[Vbear]

Gday.

Purchased a 2012 Yaris this summer. With fuel prizes soaring (along with pretty much everything else) and no EV charging ability where i live, it seemed a good solution since i commute to work. However, after putting 3000Km/~1800 miles on the Yaris, the results a pretty dismal. On average i get 33mpg and if i really struggle with it, i can push it to around 39 mpg. However at ~33 mpg im not doing any exciting driving with it. 

The car has done 200K Km, but other than that its in good shape.  So where would i start looking for the fault?  Rear brakes? DPF? Turbo?  Filters?   I plan on doing a full service before winter. But if i cant find the fault i need to change it for something else before i put to much money into it.

\\ V

[Cyker]

That's pretty bad... even when I was hooning my old Mk1 around the countryside, which had an older version of the same engine, it never did less than 50mpg!

If it hasn't already, would be worth giving it a full service - Change the oil, oil filter, air filter, fuel filter, check tyre pressures and make sure everything is nice and smooth, see how it goes.

How does it run? Exhaust clean, no weird smell or smoke? Rolls well? Wheels all spin freely? Brakes not partly stuck on or something? No weird wear patterns on the tyres that might indicate alignment problems? Clutch okay, good bite, no slipping?

Could be DPF blockage causing an obstruction, as the Yaris was often bought as a 'city car' and I can imagine it never getting a chance to regen properly due to the engine never getting loaded. If there are any DPF specialists nearby they can check it and advise.

I will say the 1ND-TV engine really likes to be loaded - It works best when it's good and hot and that also keeps it healthy as guck and deposits can be burned off by the engine heat. Driven normally, esp. at city speeds, it doesn't get that hot so it might be worth filling it up with some V-Power or whatever fancy super diesel you can get, and taking it on the fastest or hilliest roads near you and giving it a good long hoon or 'italian tuneup' to see if that helps clear its pipes.

 

[Vbear]

2 hours ago, Cyker said:

That's pretty bad... even when I was hooning my old Mk1 around the countryside, which had an older version of the same engine, it never did less than 50mpg!

If it hasn't already, would be worth giving it a full service - Change the oil, oil filter, air filter, fuel filter, check tyre pressures and make sure everything is nice and smooth, see how it goes.

How does it run? Exhaust clean, no weird smell or smoke? Rolls well? Wheels all spin freely? Brakes not partly stuck on or something? No weird wear patterns on the tyres that might indicate alignment problems? Clutch okay, good bite, no slipping?

Could be DPF blockage causing an obstruction, as the Yaris was often bought as a 'city car' and I can imagine it never getting a chance to regen properly due to the engine never getting loaded. If there are any DPF specialists nearby they can check it and advise.

I will say the 1ND-TV engine really likes to be loaded - It works best when it's good and hot and that also keeps it healthy as guck and deposits can be burned off by the engine heat. Driven normally, esp. at city speeds, it doesn't get that hot so it might be worth filling it up with some V-Power or whatever fancy super diesel you can get, and taking it on the fastest or hilliest roads near you and giving it a good long hoon or 'italian tuneup' to see if that helps clear its pipes.

 

 

Hey man. Thanks for the answer. 

It runs ok. I dont really have a comparison, but it seems a bit lacking. But i havnt driven a 1.4 diesel of any kind before. Used to roll in a Peugeot 407 with a 1.6HDI and that one were miles better.  If im anywhere under 2K rpm in the yaris i have nothing.

No smoke or anything like that. Clutch seems to have been misused a bit, but no scraping etc. Rolls well, except for too much body roll for my taste. I've driven cars with blocked DPFs before, but they always throw a CEL at you if regen isnt doing its job. Hows the Toyotas on stuff like that? 

I'm no stranger to putting a bit of load on when driving,  and my commute to work includes a fair bit of hills (I live in Norway and basically have to cross a mountain. But ah well. I have access to a workshop and will probably have to get to it. Just. This car was supposed to be a cheap daily driver that i didnt have to wrench all the time.

[Cyker]

It might be different on the Mk3, as my Mk1 was before they stuck things like DPFs and other emissions control blockages on the car, but I found the D4D's performance really good; Was the highest revving diesel I've driven, had loads of torque all through the rev range, and still returned excellent mpg.

That was compared to a small-displacement petrol car tho'.

Given that you have to cross a mountain regularly I'd think that is enough regular load to blow out any cobwebs so less likely to be the DPF I guess... bit of a head scratcher.

Could be a boost pipe leak somewhere, and vacuum line leaks can also cause weird performance problems. MAF sensor might be worth taking out and cleaning with some switch cleaning spray as a precaution. 

 

Must admit it's a bit funny hearing a norwegian with a diesel car; The way your country is portrayed it sounds like almost everyone has an EV!   

[Bruce Lea]

Drive it motorway for good 1hr will help clear any filter blocks

[jcps001]

On 8/16/2022 at 7:53 PM, Vbear said:

Gday.

Purchased a 2012 Yaris this summer. With fuel prizes soaring (along with pretty much everything else) and no EV charging ability where i live, it seemed a good solution since i commute to work. However, after putting 3000Km/~1800 miles on the Yaris, the results a pretty dismal. On average i get 33mpg and if i really struggle with it, i can push it to around 39 mpg. However at ~33 mpg im not doing any exciting driving with it. 

The car has done 200K Km, but other than that its in good shape.  So where would i start looking for the fault?  Rear brakes? DPF? Turbo?  Filters?   I plan on doing a full service before winter. But if i cant find the fault i need to change it for something else before i put to much money into it.

\\ V

Look at your MAF sensor. If it is dirty, clean it very well with MAF sensor cleaner. Experience the difference.