I often find slow traffic ahead of me prevents me from accelarating anywhere near best BSFC. There are two usual ways of coping with this: less load and shifting at lower revs. Both of thease sacrifice efficiency.
Lately however, i have been using a third method: coast a bit between gears, this alows more efficient acceleration at the same average rate.
In reality, of course, it's a compromise - you can't be too jerky in dense traffic.
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2016: 128.75L for 1875.00km => 6.87L/100km (34.3MPG US)
2017: 209.14L for 4244.00km => 4.93L/100km (47.7MPG US)