Prius 10 mpg drop after first service

[birdseye]

My 2016 Prius had it's first service in Dec ( 5800 miles) and my mpg has noticeably dropped regardless of the cold weather. I think I'm down 10mpg and I'm wondering if it's anything to do with oil? either the wrong grade or overfill?

The oil is right up to the high mark on the dipstick but it's original factory fill I seem to recall it was halfway between low & high & I'm well aware that for hybrids it's important to not overfill.   Is the overfill likely to be the culprit or can it be something else that originates from the service?

 

[FROSTYBALLS]

Do you know what grade of oil was used? Should be 0W-20.

[birdseye]

I don't know what grade of oil was used, it was done at a Listers Totota, I'm wondering if it might be an incorrect grade but if I go to the dealers I expect they will say it was filled correctly

[PeteB]

Did the invoice state the grade?  It doesn't guarantee that's what they actually used, but if it states the wrong one...

[wass]

Maybe someone else would be good enough to confirm, I think that the manufacturers recommend 5/30 to be used if 0/20 is not available. I routinely changed the oil immediately after  using the first tankful after my car was serviced and refilled with my own Toyota 0/20.  I suspect that it is popular for many dealers to not stock 0/20 or run out of it at the precise time of servicing and to use the "recommended" 5/30. When challenged, my servicers always professed to be using the "recommended oil" but they never detailed the grade on the invoice when requested and would never detail the grade when challenged. You'll be surprised to hear that after draining out the new oil provided by the servicer and replenishing with my own Toyota 0/20, my fuel consumption always returned to what it should be. I never took much notice of the fuel consumption on the tank full during the service because the car was always collected from us and  returned to us by the dealers driver. My fuel consumption did indeed increase by an amount but it was closer to 5% than 10%. I never was able to get any satisfactory resolution to this phenomenon but my already low opinion of the motor trade wasn't improved.

[16_Auris_HSD]

They buy oil in barrels and so it wouldn't surprise me at all if an incorrect but still within spec oil was used because it's cheaper for them not to stock too many types at the same time.

[PeteB]

2 hours ago, wass said:

Maybe someone else would be good enough to confirm, I think that the manufacturers recommend 5/30 to be used if 0/20 is not available...

This is what's in the Gen 3 Prius manual:

Oil grade: 0W-20, 5W-20, 5W-30 and 10W-30: API grade SL “Energy-Conserving”, SM “EnergyConserving”, SN “Resource-Conserving” or
ILSAC multigrade engine oil 15W-40 and 20W-50: API grade SL, SM or SN multigrade engine oil

and for Gen 4 Prius:

Oil grade: 0W-20, 5W-30 and 10W-30: API grade SL “Energy-Conserving”, SM “EnergyConserving” or SN “Resource-Conserving”; or
ILSAC multigrade engine oil 15W-40: API grade SL, SM or SN multigrade engine oil

The only differences I can see are 2 grades specified for the Gen 3 that are not in the Gen 4 list.  I've highlighted them in red.

[FROSTYBALLS]

In addition to the oil specifications listed in the owners manual, Toyota usually state which is their 'preferred oil'.

For Optimal Drive petrol engined, non-hybrid models it is 0W-20. 

Manuals also state:

"SAE 0W-20 is filled into your Toyota vehicle at manufacturing, and the best choice for good fuel economy and dfood starting in color weather.

If SAE 0W-20 is not available, SAE 5W-30 may be used. However it should be replaced with SAE 0W-20 at the next oil change.

This has been the case with my 2009 and 2012 Auris and my current Aygo - and will be the same for the Prius.

Having said that, under Block Exemption, Toyota cannot make their dealers use a particular oil. Also see 

 

[birdseye]

Thanks for replies everyone,

I'm going to the dealership tomorrow to see if I can find out what oil they used,  if it's not 0W-20 then I presume I can't make them change it although filling to the top dipstick mark is also incorrect as in the handbook it shows the top mark as ' excessive'

[QuantumFireball]

Don't know about the UK, but it's fairly common for Toyota dealers in Ireland to just use 5W-30 on the hybrids, unless specifically asked to use 0W-20 (and they will charge more for this). Mine has 5W-30 in it now, but I can't say what was in it when I got the car (bought it in NI).

[FROSTYBALLS]

5 minutes ago, QuantumFireball said:

Don't know about the UK, but it's fairly common for Toyota dealers in Ireland to just use 5W-30 on the hybrids, unless specifically asked to use 0W-20 (and they will charge more for this). Mine has 5W-30 in it now, but I can't say what was in it when I got the car (bought it in NI).

In my last three Toyotas (two petrol Auris and an Aygo) I have asked for 0W-20 to be used and not been charged extra. For my last and my present car, I've had 0W-20 stipulated in the service plans. The grade of oil used is included on the service invoices.

If your Prius Plug In was bought new, it would have been filled with 0W-20 at the factory.

[QuantumFireball]

I bought it in 2016. Actually, the UK service history does say "0W20 TGMO ENGINE OIL" on some of the services (including the last before I got it).

If you didn't ask for 0W-20, would they have used 5W-30?

[FROSTYBALLS]

11 minutes ago, QuantumFireball said:

I bought it in 2016. Actually, the UK service history does say "0W20 TGMO ENGINE OIL" on some of the services (including the last before I got it).

If you didn't ask for 0W-20, would they have used 5W-30?

Possibly 

[MEP's Yaris GS]

On my most recent PiP service the dealer had used 0w30 - luckily I noticed this on the paperwork before leaving.

They promptly changed it to 0w20 after they realised I wasn't going to leave until they had done. Upon checking the previous services where 0w20 had been used, it saves them £10 a time (although you're still charged the same price as its under their fixed pricing servicing scheme), soon adds up over a few hundred cars.

Out of 6 services they've made errors on 3 - not very good for a franchised main dealer. My only saving grace is they've always gone out of their way to rectify the issues.

[Chris Dance]

I  believed this problem had been sorted and Toyota had informed all dealers to use OW20 on Gen 3 and 4 Prius. The last time I asked our local dealer about this issue I was told they always use OW20 on Gen 3 and 4.  Our car is due service in February I will raise this issue again with the dealer. On my previous services on Gen 3s only OW20 was used.

[FROSTYBALLS]

2 minutes ago, Chris Dance said:

I  believed this problem had been sorted and Toyota had informed all dealers to use OW20 on Gen 3 and 4 Prius. 

Under Block Exemption Toyota cannot insist dealers use a particular oil. 

[MEP's Yaris GS]

5 hours ago, FROSTYBALLS said:

Under Block Exemption Toyota cannot insist dealers use a particular oil. 

Not even when servicing under Toyota UK's very own 'Fixed Price Servicing' Scheme?

If so thats every poor, as its supposed to provide clarity that you're getting the same from what ever deal you visit in the UK for the same price, which clearly isn't the case if they can use what ever oil they wish.

[FROSTYBALLS]

6 hours ago, FROSTYBALLS said:

Under Block Exemption Toyota cannot insist dealers use a particular oil. 

 

8 minutes ago, MEP's Yaris GS said:

Not even when servicing under Toyota UK's very own 'Fixed Price Servicing' Scheme?

If so thats every poor, as its supposed to provide clarity that you're getting the same from what ever deal you visit in the UK for the same price, which clearly isn't the case if they can use what ever oil they wish.

Block exemption applies to any servicing scheme within the new car warranty period, regardless of manufacturer or whether the scheme is fixed price or otherwise.

It is an EU regulation, and nothing the manufacturers can do anything about.

[16_Auris_HSD]

7 hours ago, FROSTYBALLS said:

Under Block Exemption Toyota cannot insist dealers use a particular oil. 

By "particular oil" surely it refers to being unable to force dealers to use particular brand/type, rather than grade.

[FROSTYBALLS]

25 minutes ago, 16_Auris_HSD said:

By "particular oil" surely it refers to being unable to force dealers to use particular brand/type, rather than grade.

Toyota have specified that, although 0W-20 is the preferred oil, 5W-30 may also be used. In which case they cannot stipulate to their dealers that only one of those grades must be used.

[birdseye]

I went to the dealers today but it was a struggle to get any sense to start with, the service manager started of with saying it was filled with 0W-20 and it was not possible to put the wrong oil in & droned on about about cold weather might have caused it etc. Anything I read on Toyota owners forums will most likely be incorrect etc.

Then said I'll have to run the tank to the red light & fill to the brim & take note of how many miles when it went back to red,  repeat it again & then he can send the results to Toyota etc.

After half an hour of arguing he agreed to personally oversee the car drained the oil & refilled if we left the car for two hours so we returned later & collected the car, I've only driven the 12 miles home so can't tell for sure yet but I've got a feeling already that it's still not right.

[Mooly]

On ‎15‎/‎01‎/‎2018 at 10:20 AM, FROSTYBALLS said:

In my last three Toyotas (two petrol Auris and an Aygo) I have asked for 0W-20 to be used and not been charged extra. For my last and my present car, I've had 0W-20 stipulated in the service plans. The grade of oil used is included on the service invoices.

If your Prius Plug In was bought new, it would have been filled with 0W-20 at the factory.

When my 2010 Auris (1.33L) was new and having its first few services (on a 7yr service plan) I used to ask what oil was used and the reply was often 5W-30 semi synthetic. In the last few years they always say 0W-20.

I have no real comprehensive documentation for any service stating what is actually used, and this was in fact a major whinge of mine over the service plans. I was told the paperwork was sent to the plan administrators.

Curiously now at 8 yrs old and 52K miles I find oil consumption has become noticeable and requires around 1.5L annually to keep it in the 50 to 100% range of the dipstick. I asked last year whether a switch to 5W-30 or even 10W-40 would be of benefit and was told 'definitely not' and that 0W-20 must always be used. They however used the higher viscosity grades for quite some time until I believe Toyota instructed otherwise.

I really do wonder whether the thin oils offer the all round protection needed, particularly when longer higher speed runs are the norm. 

[johalareewi]

A little late to the party but have you checked the tyre pressures?  It is not unknown for LRR tyres to be under inflated after a service (maybe the mechanic set the tyre pressures for non LRR tyres).  A 2 or 3 PSI under inflation makes a noticable dent in hybrid mpgs.

[FROSTYBALLS]

When I took out the service plan on my Aygo in September 2016, the service manager queried why I wanted the use of 0W-20 written into the plan, as for petrol models they usually use 5W-30.

Usually with service plans, the invoices do go to the plan management company. I have written into my plan that copies of the invoices are supplied. Did this with my previous Auris as well.

[MEP's Yaris GS]

3 hours ago, birdseye said:

I went to the dealers today but it was a struggle to get any sense to start with, the service manager started of with saying it was filled with 0W-20 and it was not possible to put the wrong oil in & droned on about about cold weather might have caused it etc. Anything I read on Toyota owners forums will most likely be incorrect etc.

Then said I'll have to run the tank to the red light & fill to the brim & take note of how many miles when it went back to red,  repeat it again & then he can send the results to Toyota etc.

After half an hour of arguing he agreed to personally oversee the car drained the oil & refilled if we left the car for two hours so we returned later & collected the car, I've only driven the 12 miles home so can't tell for sure yet but I've got a feeling already that it's still not right.

Have you checked what was listed on the paperwork when you paid for the completed service?