0W-20 For Better Fuel Economy

[NGRhodes]

29 minutes ago, TonyHSD said:

I know that too, but most likely to be a myth although make some sense. If for some reason you had been using  5w30 or other type of oil instead of 0w20 since the early days of the car damage may had been done and cylinders worn out, piston rings stuck and carbon built up on some parts of the top end due to a different properties of the oil, then after you switch back to its manufacturer recommended grade which turns to be thinner low viscosity oil with greater cleaning agents and better fluidity may cause noises and higher oil consumption., for that reason alone simply stick with what is recommended in the book and don’t change oil viscosity on your own. I wonder what oil Prius owners use in Dubai?, perhaps 0w20 even it’s 40C° for long periods of time during the year . 

With ACEA Euro spec oils, the wear and carbon deposit tests are either similar or identical between different oil grades/specs, the main differences are DPF compatible or not, viscosity and intended service duration.
I suspect the origins of advice of using a thicker oil for high milage stem from older, lower tolerance engines that did wear and leak/burn oil, but modern engine made in atleast the last 25 years is much more durable.
Combine this with the fact that modern oils are really really good (since the usage of synthetics and advanced tribology leading to a far better understanding of engine conditions and development of really good additive packs), I know someone who drives an 80s Saab turbo 650km a week on the autobahn, who uses Shell 0w30 (on a car intended to use 15w40), he does regular used oil analysis (no excess metals for wear, additives still not deplenished) and has stretched his service interval to 20000km because the oil is lasting so well !

[NGRhodes]

10 minutes ago, Catlover said:

Remember Tony, it’s 0w-16 now for (at least) Prius. As :r T has been putting in 0w-20 for the first 4 year 21 months of my motors life I hope everything is going to be ok now Mr T put 0w-16 in.

Toyota have done this a number of times, I would not be worried. Toyota has a habit of not rushing to be an early adopter of thinner oils and spend more time testing before announcing a thinner oil is suitable. Toyota engine designs tends to be very tolerant of different grades/quality of oil compared to Euro manufacturers.

[Cyker]

Yeah, the only reason to go thicker is if the engine is going to be really hot for long periods, e.g. a track day, as the oil will thin out more at higher temperatures.

With hybrids, because the engine is barely at operating temperature most of the time and is usually under relatively light load (Mine will happily do 2000rpm at 70mph, assuming the engine bothers to turn on at all!  ), thinner oils are actually better because they circulate faster and fit the razor thin tolerances, which thicker oils have trouble flowing through.

Just be glad yours is using a grade that's available - Mine is rated for 0w8, which even my Toyota dealer doesn't have stock of 1L top-up bottles yet! (And as the oil level has barely changed since I got it, unlike my oil guzzling Mk2, I don't really want a 5L bottle  )

[TonyHSD]

27 minutes ago, Cyker said:

Yeah, the only reason to go thicker is if the engine is going to be really hot for long periods, e.g. a track day, as the oil will thin out more at higher temperatures.

With hybrids, because the engine is barely at operating temperature most of the time and is usually under relatively light load (Mine will happily do 2000rpm at 70mph, assuming the engine bothers to turn on at all!  ), thinner oils are actually better because they circulate faster and fit the razor thin tolerances, which thicker oils have trouble flowing through.

Just be glad yours is using a grade that's available - Mine is rated for 0w8, which even my Toyota dealer doesn't have stock of 1L top-up bottles yet! (And as the oil level has barely changed since I got it, unlike my oil guzzling Mk2, I don't really want a 5L bottle  )

Once I had taken my hybrid on euro trip  and was baking hot at the time, continues long hours driving through this heatwave 39C° and at high speeds but no oil was consumed at all or anything bad had happened, the car is still alive. 😊

[Cyker]

I have to say it's really nice cruising in a hybrid, esp. with the cruise control on - The car will just settle to diesel-levels of RPM, if it even bothers using the ICE at all, so you can't even hear any engine sound unless you give it the beans. Very pleasant compared to the constant 3000rpm+ drone of my old Mk2!! Argh my ears twitch just remembering that! Was not a nice feeling, finishing every long trip with tinnitus!

Even better since I swapped to 15"'s, which has gotten rid of a lot of the road noise to boot! (Why they don't offer 15" as an option I'll never understand - The car is sooo much better for it over the 17's!)

 

[Mikw]

6 hours ago, Cyker said:

Yeah, the only reason to go thicker is if the engine is going to be really hot for long periods, e.g. a track day, as the oil will thin out more at higher temperatures.

With hybrids, because the engine is barely at operating temperature most of the time and is usually under relatively light load (Mine will happily do 2000rpm at 70mph, assuming the engine bothers to turn on at all!  ), thinner oils are actually better because they circulate faster and fit the razor thin tolerances, which thicker oils have trouble flowing through.

Just be glad yours is using a grade that's available - Mine is rated for 0w8, which even my Toyota dealer doesn't have stock of 1L top-up bottles yet! (And as the oil level has barely changed since I got it, unlike my oil guzzling Mk2, I don't really want a 5L bottle  )

I hear you! I did manage to get a one litre bottle of 0w8 after some pushing, but it wasn't cheap. Glad the car is not an oil burner, it would cost a fortune in oil, if you can even find it at all.

You're quite right, the new Yaris cruises at low revs on the motorway once 70 is reacheg, just bung the cruise control on and hold the wheel, and it settles down nicely.

[Vandals01]

6 hours ago, Cyker said:

Even better since I swapped to 15"'s, which has gotten rid of a lot of the road noise to boot! (Why they don't offer 15" as an option I'll never understand - The car is sooo much better for it over the 17's!)

Because it looks cool.  Big Rims, Low Profile tyres is a FASHION.

To be fair, larger wheel and low profile DO gives better Handling and Road FeedBack BUT in-exchange for Comfort.

Furthermore, low profile tyres are more likely to be damage by Potholes.

 

[Mikes1992u]

The thing is despite the 2012 Aygo and onwards recommending 0w20 (the newer model recommends 0w16) in the service book the Toyota garages still fill it with 0w30 or 5w30. It does make me wonder if the drop in tax band required them to say it takes 0w20 (to drop from £20 to £0). The new design Aygo is supposed to get better fuel economy but the user data actually suggests it is actually lower economy then the older models (which could also be because it appeals more to spirited drivers?)

[Yugguy1970]

I'm of an age where rims that are too big make the car look like the one Noddy used to drive. 😅

[Guest]

16 hours ago, Cyker said:

I have to say it's really nice cruising in a hybrid, esp. with the cruise control on - The car will just settle to diesel-levels of RPM, if it even bothers using the ICE at all, so you can't even hear any engine sound unless you give it the beans. Very pleasant compared to the constant 3000rpm+ drone of my old Mk2!! Argh my ears twitch just remembering that! Was not a nice feeling, finishing every long trip with tinnitus!

Interesting, but in what way relevant to us Aygo owners?

[FROSTYBALLS]

Please return to the original subject - 0W-20 for better fuel economy in the Aygo (non-hybrid).

[SimonIG10]

I think on these rattly older Aygo engines you are gonna go though a lot of oil top ups using this very thin 0 grade. Unless you live in a very cold area of the Uk etc 5w30 surely is best bet. i may even go 5w40 to stop it losing oil once hot. 5w 30 is quite cheap as well for decent stuff. Oil likle Castro Edge is daylight robbery in my opinion and any saving using stuff like this will eat into any supposed fuel economy savings.

[Mikes1992u]

To be honest the fuel savings with 0w20 wasn't really noticeable. I hypermile my Aygo and average over 70mpg over the full year (72-78mpg over the summer and 67-73mpg in the winter) and 0w20 hasn't really changed my average figures. Its probably not advisable but I usually fit a grill block for the cold winter months and use the heating system to remove any extra heat from the engine (which isn't really allot when it's freezing outside) by monitoring the coolant temperature (target temp is around 84-85c).

[Gerg]

32 minutes ago, Mikes1992u said:

0w20 hasn't really changed my average figures

I take it you were using 5w/30 beforehand?

34 minutes ago, Mikes1992u said:

I usually fit a grill block for the cold winter months

Do you have any figures for how much an improvement the grill block offers? 

What percentage of the grill is blocked?  I have tried similar on other cars, but never got to work out mpg improvements.

Sounds interesting!

TIA

[Mikes1992u]

On 9/10/2021 at 4:26 PM, Gerg said:

I take it you were using 5w/30 beforehand?

Do you have any figures for how much an improvement the grill block offers? 

What percentage of the grill is blocked?  I have tried similar on other cars, but never got to work out mpg improvements.

Sounds interesting!

TIA

Depending on temps I start with half and then a full block once temps are consistently in the negatives. A grill block doesn't offer much benefit when you're first starting the car and driving it on a cold morning but it does improve warmup time quite significantly once you do start moving (since the engine hasn't got cold air blowing against it). Once the engine is warm under bonnet temps can raise to around 20c when it's -4c outside, without it the air around the engine would probably be around 6-9c. I still rarely see coolant temps above 83c even with a full block. The fuel economy once the engine is warm is close to that of driving in summer, the biggest hit for me is the initial cold start and anything that helps speed up the precess makes a massive difference. I have wondered if you could fit a hot water storage tank but I really wouldn't want to risk messing around with the flow of coolant.

[Mikes1992u]

I just topped up my oil after 1,500 miles with 5w30 and it's burned about 200ml, estimated burn rate for 5,000 miles would be ~666mls (which is aroundwhat I've been seeing on previous services, its just above the Min marker on the dipstick at 5,000 miles) Vs the ~1.4L it used with 0w20. I am keeping a close eye on oil level now. 

 

I don't know why I assumed 0w20 would burn at the same rate as 0/5w30... It's a shame these engines burn oil, from what I've read it's normal. Guess I have got 85,000 miles on the engine now but the oil burning became noticeable from about 40,000 miles. I was hoping to keep the car running for at least 160,000 miles hopefully the burn rate doesn't keep increasing up till that point... I guess if I'm happy with the state of the car I could always fit a new engine if it does become a problem.