Differences in fuel consumption Auris HSD 2014 /16?

[HSDish]

Seems like my Auris hatchback 2016 HSD consumes a bit more fuel than my Auris Touring Sports 2014 HSD.

Got 17” wheels on the 2016 HB HSD and 16” on my 2014 TS HSD,  though (maybe why theres a difference in fuel consumption.

Is there any official/common known differences in fuel consumption between Auris HSD 2014 and 2016 models?

[FROSTYBALLS]

The lower profile tyres on the 2016 car will slightly affect fuel consumption.

For example, Toyota's figures for the 2013 Touring Sports Hybrid were EU combined fuel consumption 76.3mpg for cars with 15 inch wheels, and 70.6mpg  for cars with 17 inch wheels. So 16 inch wheels will come somewhere between the two. 

Engines from March 2015 were EU6 compliant - not sure whether that may or may not also have a slight effect.

[HSDish]

1 hour ago, FROSTYBALLS said:

The lower profile tyres on the 2016 car will slightly affect fuel consumption.

For example, Toyota's figures for the 2013 Touring Sports Hybrid were EU combined fuel consumption 76.3mpg for cars with 15 inch wheels, and 70.6mpg  for cars with 17 inch wheels. So 16 inch wheels will come somewhere between the two. 

Engines from March 2015 were EU6 compliant - not sure whether that may or may not also have a slight effect.

Appreciate Your support. 

Thanks!

Probably the wheels, then

[PeteB]

6 hours ago, FROSTYBALLS said:

...Toyota's figures for the 2013 Touring Sports Hybrid were EU combined fuel consumption 76.3mpg for cars with 15 inch wheels, and 70.6mpg  for cars with 17 inch wheels...

Mostly, the overall diameter and circumference of the outside edge of the tyre will be almost exactly the same, the larger diameter rims tend to carry lower profile tyres so there's more metal and less rubber between the car and the road on the larger wheels.  This is part of the reason cars with the larger wheels are noisier, have harsher rides and are slightly more likely to be damaged by a very severe pothole.

However, on many Toyota (and probably other makes) the cars with larger rims also have tyres that are wider, and it's this that adversely affects mpg, CO2 emissions and the CD (Coefficient of Drag).  Apart from Frostyballs' example, Prius and Yaris Hybrid models with larger wheels also have worse figures than those with smaller rims.  Another byproduct is that the turning circle can be significantly poorer with the wider/larger rims.  Both Gen 3 & 4 Prius had a CD figure that was 0.02 worse with the larger rims, which despite being a small number, is a very large difference.

There may be other factors at play too, such as the CD of the car itself, and it may be the Auris TS shape has a better figure than the hatchback (I don;t know any CD values for Auris models), which again would affect mpg.

[HSDish]

25 minutes ago, PeteB said:

Mostly, the overall diameter and circumference of the outside edge of the tyre will be almost exactly the same, the larger diameter rims tend to carry lower profile tyres so there's more metal and less rubber between the car and the road on the larger wheels.  This is part of the reason cars with the larger wheels are noisier, have harsher rides and are slightly more likely to be damaged by a very severe pothole.

However, on many Toyota (and probably other makes) the cars with larger rims also have tyres that are wider, and it's this that adversely affects mpg, CO2 emissions and the CD (Coefficient of Drag).  Apart from Frostyballs' example, Prius and Yaris Hybrid models with larger wheels also have worse figures than those with smaller rims.  Another byproduct is that the turning circle can be significantly poorer with the wider/larger rims.  Both Gen 3 & 4 Prius had a CD figure that was 0.02 worse with the larger rims, which despite being a small number, is a very large difference.

There may be other factors at play too, such as the CD of the car itself, and it may be the Auris TS shape has a better figure than the hatchback (I don;t know any CD values for Auris models), which again would affect mpg.

Thanks a lot.

I understand that there is a lot of circumstaneces to consider. Verry interessting though

[FROSTYBALLS]

According to Toyota, the CD for the Auris hatchback is 0.28 and the Touring Sports 0.29.

[PeteB]

1 minute ago, FROSTYBALLS said:

According to Toyota, the CD for the Auris hatchback is 0.28 and the Touring Sports 0.29.

Are there different CD values for different wheel sizes as there were for Gen 3/4 Prius?

[FROSTYBALLS]

No - unlike the first generation Auris, for the second generation (Dec 2012 onwards) they just split the information into the petrol, diesel and hybrid models. Although the 1.33 and the hybrid Touring Sport had the same CD.