Fuel Economy Difference In The Various Models Of 300H

[Activ8]

Today my F-Sport was at the dealer having a couple of dealer fit parts fitted and I had the Luxury model for the afternoon. Two observations... I got better fuel economy on the identical run by about 8 mpg the website states 5mpg better for the luxury... I had wondered why the difference is quite big given that the website states power and weight and performance are the same... however driving the luxury after the sport the throttle response is very different in the different modes... Eco in the F-Sport feels somewhere between eco and normal in the Luxury and sport mode in the luxury fells like normal+ in the F-Sport and Sport mode in the luxury is nowhere near as aggressive on the throttle as it is in the F-Sport. Speaking with the service technician afterwards he told me that he believes the computer mapping is different and that the F-Sport and Premier have much more aggressive map which has both engines working together more often.

I don't think unless you jumped out of one and straight into another you would notice much performance difference between the two well apart from the fuel economy that is!

[DJP]

That's interesting stuff. Does the F Sport have bigger wheels too? That would make a difference too wouldn't it?

What did you have fitted?

[powerkitten]

That makes me feel a little better, as I am currently getting around 42mpg. I have done over 650 miles, I try to get up to speed,take the foot off, and then just use the electric power, longer breaking etc but struggle to get much above that at the moment. I do find the petrol engine very keen to join in, so maybe there is a difference between models. I do drive predominantly on motorways, is that bad for fuel economy, would I be better off taking a roads instead!

[Activ8]

That's interesting stuff. Does the F Sport have bigger wheels too? That would make a difference too wouldn't it?

What did you have fitted?

I have the 18's This would make a small difference to MPG as the wider rubber has more friction but should be no more than around 2mpg or so. If there was a big difference to the wheel tyre weight there maybe another 1mpg to add. As the rolling size is very similar acceleration and other performance should be the same.

That makes me feel a little better, as I am currently getting around 42mpg. I have done over 650 miles, I try to get up to speed,take the foot off, and then just use the electric power, longer breaking etc but struggle to get much above that at the moment. I do find the petrol engine very keen to join in, so maybe there is a difference between models. I do drive predominantly on motorways, is that bad for fuel economy, would I be better off taking a roads instead!

In reality I think we are going to average mid to late 40's in the F-Sport or Premier driving normally with the luxury early to mid 50's driving normally would seem the norm. The cars will get better with 3-5K miles on them.

[Roger Bill]

The IS brochure quotes different mpg and CO2 figures for the three different wheel sizes but no difference for the F Sport/ non-F Sport models. Mpg figures for 16"/17"/18" wheels are 65.7/64.2/60.1 and CO2 figures are 99/103/109.

I'd guess these differences are mainly caused by the different tyre widths: 205mm for 16" wheels, 225 for 17" and 225 front/255 rear for 18". A simple calc (225 +255) / 2 gives an average tyre width of 240mm for 18" wheels which is 6.7% greater than the 225mm 17" tyres, almost exactly the same as the 6.8% difference between 60.1 and 64.2mpg!

Obviously these government mpg figures aren't achievable in normal driving but I think do provide a rough relative yardstick for comparing different cars and specifications. However, David found an even bigger difference in the mpgs of the Luxury and his F Sport so maybe the more sporty settings encourage more enthusiastic use of the loud pedal!!

[Activ8]

Good point Roger... I forgot that they did 16" wheels that could account for much more than my 18" ones although I did think they were 17's on the car I tested... Maybe someone with 16's would do much better. I do think that the mapping on the F-Sport and premier encourage more sporty driving due to steering weight and sharp throttle response. I doubt that there is any real performance difference between the models... be an interesting drag race though!

[Silver Arrow]

I found that with Hybrids, trying to take off gently and in electric mode only for as long as possible makes a huge difference - most of the petrol is consumed by the car in first and 2nd gear speeds whilst accelerating, which careful driving will avoid by using more electric power.

In the CT200h, I could easily manage 65+mpg around town, but boy you have to try hard.