Increased fuel consumption after 60K service

[nielshm]

My car has just had it 60K miles service done. Since day 1, my fuel consumption has gone up by 10%, so I'm pretty sure that something has happened. 

Could it be software updates that makes such big differences? My car has CVT, so it could be updates to both engine and gearbox. 

Has any one tried something like this? 

[Gerg]

11 hours ago, nielshm said:

 Since day 1, my fuel consumption has gone up by 10%, so I'm pretty sure that something has happened. 

 

Do you mean that since you bought the car the fuel consumption has got worse?  Or, since the service it has got worse?

[nielshm]

Since the service. I drive the same route to work every day, samt speed, same traffic. It's very clear, that something has changed.

[Gerg]

I imagine that you are asking if there are any mandatory code upgrades for your car, and if so, what do they do, in which case only a few people will be able to answer on here.

But, in case that isn't what you were thinking then, off the top of my head these suggestions come to mind:-

(You seem to know your car very well, so most of these questions will already have been considered by you).

Have you informed the garage that did the service that your mpg has dropped? If so, what did they say? Were you ever informed that an ECU upgrade was going to be performed?  Does the car feel less energetic?  When the car has got wet, does one wheel dry faster than the others after a drive? (i.e. brake dragging after strip-down).  If the car is allowed to coast to a complete halt, does it stop with a tiny jolt? (i.e. brake dragging after strip-down).  Have the tyre pressures been checked since the service?  Does the engine feel *slightly* smoother since the service? (i.e. has a 5w/30 grade of oil possibly been used).  Was a wheel alignment check done (with a consequent adjustment)?  Have they charged you for a new set of spark plugs? (Correct ones fitted?).  Does the handbrake adjustment seem to have changed?

Just as a reminder in the unlikely event that you don't have a service schedule, in the UK a full service would consist of these items:-

Check radiator and condenser 
Check seat belts 
Check steering wheel 
Check valves^† 
Check warning lights 
Check washers 
Check wipers 
Clear airflow meter^† 
Diesel smoke test 
Drain engine oil 
Free Hybrid Health Check^† 
Free Visual Safety Report 
Free Wash and Vac 
Full 4-wheel alignment check^* 
Inspect air filter^* 
Inspect brake lining and drums 
Inspect brake pads and discs 
Inspect charcoal canister^*†2 
Inspect drive shaft boots 
Inspect exhaust pipes 
Inspect fuel and brake pipes 
Inspect glass and light lenses 
Inspect hand brake 
Inspect spark plugs 
Inspect steering 
Inspect suspension ball joints and dust covers 
Inspect suspension for security and leakage 
Inspect transfer box oil^† 
Inspect transmission oil^* 
Inspect tyres 
Inspect wheel bearing 
Inspect wheels 
Lubricate prop shaft joints^† 
Recheck all levels 
Recheck for fluid leaks - underside and engine bay 
Refill Ad-Blue^† 
Refill engine oil 
Refill Screenwash 
Replace Battery in locking remote 
Replace cabin air filter 
Replace front and rear differential oils^† 
Replace fuel filter^† 
Replace gear oil^† 
Replace oil filter 
Replace sump washer 
Reset service lights and monitor as required 
Tighten prop shaft bolts^† 
Torque tighten wheel nuts 

_{Symbol Guide 
*- Additional Charges apply if work is required. 
†-Model dependant. 
1- Initially 60,000 miles, thereafter every 10,000 miles or 1 year. 
2- AYGO charcoal canister filter replacement every 60,000 miles.}

It is possible to crudely get an idea of the oil viscosity that is now in the engine, but before you can do that you need to be able to get some of it out, and have some 0w/20 or 5w/30 to compare it to.  I just use a 30ml syringe and some very thin plastic pipe, but many people don't have these knocking around in their garage.

[TonyHSD]

You can double check what oil grade has been filed into the engine, change from 0w20 to 5w30 is most likely reason, and happens to many owners, Toyota dealers practice, also you can double check tyres pressures on cold tyres with a precise tool to make sure they are all correct no more no less than the recommendation, and these days weather is colder than last week which probably help reduce the efficiency. 

Regards 

[FROSTYBALLS]

Although 0W-20 oil is the preferred oil for most hybrids and recent petrols, Block Exemption doesn't allow Toyota to insist a certain grade of oil is used by Toyota dealers. So the dealer may or may not have used 5W-30.

[TonyHSD]

Yes sure, but from owners point of view, why would you filled an oil grade that will degrade your efficiency? We drive hybrids to get best efficiency out of them , plus other benefits whatever, . doesn’t make sense to drive a Toyota hybrid filled with 5w30 oil and UHP low profile tyres that will affect the fuel economy drastically. If the car comes from factory with 0w20 oil inside the engine I would expect from the dealer to put the same oil in during service, and not trying to be smart. So they make more money on me, savings from cheaper oil that increase my fuel consumption so I pay more at the pump, not good. 👎

[Heidfirst]

Niels, when was the service carried out?

[FROSTYBALLS]

15 minutes ago, TonyHSD said:

If the car comes from factory with 0w20 oil inside the engine I would expect from the dealer to put the same oil in during service

Legally Toyota cannot insist 0W-20 is used. One way round this is to inform the servicing dealer that 0W-20 is used when the car is taken in for service.

Aside from that the OP doesn't have a hybrid. 

What oil is listed on the service invoice?

[TonyHSD]

Oh yes 1.2t, but in any ICE use of different oil will increase fuel consumption slightly. Anyway in this case might not be the oil to blame, we can’t say anything for sure , it might be the fuel. Did he refill the same garage or different. I fill up my tank 3-4 times a week and there is a big difference between the different garages. Lately BP are best of All 488 miles range compared to 442 from Tesco and 434 Sainsbury’s, even these numbers are very average the car feels much more responsive to drive with BP petrol than supermarkets ones.

[nielshm]

My 10% has come back, and you wont believe how. I has often bought fuel system cleaners, probably without any effect at all. This time I got a Fuel Injector Cleaner, and what a difference. 

Something has been clogged up, and has now been cleaned out. 

The improvement in fuel economy is so significant, that my own variation in speed or driving style, can't make such difference by it self.