::.. Chip back to stock for winter?

[JonE]

Well I notice in winter, I'm pulling about 14-16L/100KM versus only about 10-11L/100KM in warmer weather. That's a pretty ugly difference when the commute to work is/sometimes 90km round trip.

So with conservative and simple math, assume 100km round trip (include some weekend driving). Makes 500km a week. Assume 14L/100KM chipped or not. That's 70L a week (tank!). The difference is about 9c for 'standard' to 'premium' making $6.30 a week more or $75.60 for three months of winter. I'm getting married so every penny counts

I recommend factoring in the additional "chipped" MPG into the calculation. For example, my 535 can get about 18mpg in "chipped" city driving vs. about 16mpg "unchipped". At a 10cent difference/gal in premium vs regular gas running $2.20 and say, $2.10 respectively, I am actually doing slightly better economically "chipped" and running premium gas. I like that situation. Even if the cost/gal difference is a bit higher than 10cents, I do not fret. I have a station that sells premium 90 octane at the same rate as regular, and, as I rarely let the tank get less than half empty, I'll run 90 octane and then blend with the more expensive 92 octane every other fill-up. Either way, I win and get to keep my chip! The 535i seems to run better chipped and have noticed absolutely no pinging with the 90 octane/92 octane gas blend.

[Sweet535i]

I'm getting 18.5 mpg around town...unchipped.