I tried the eco friendly routing on a few softwares; I think https://maps.openrouteservice.org does it and our car also. In both cases, it turns highway traffic into city and B-road/Landstraße traffic.
This is counter-productive: it produces more CO2 for all the braking and accelerating.
What you need to do is don't drive 130 but drive 100 on the highway. Go behind a truck if you are okay with going that slowly (not to avoid wind, afaik then you'd have to be unsafely close, but behind a truck you cannot annoy other people because they need to overtake the truck anyhow). The downside: on an average commute of like 20 minutes, that costs you probably like 2 minutes extra (since top speed is far above average speed usually). The upside: your fuel consumption (fuel burned = CO2 created) is cut nearly in half, at least for the highway part of the trip. No braking also means less particulate matter from brake wear; no shifting back means less partial combustion. Or so I've read.
The most efficient speed (afaik): as slow as your car allows (~1000 rpm) in the highest gear it has.
I hope it goes without saying, though, that one should prioritize safety (go with the flow; worse/more(?) accidents happen in high speed difference zones) over efficiency gains.
This is counter-productive: it produces more CO2 for all the braking and accelerating.
What you need to do is don't drive 130 but drive 100 on the highway. Go behind a truck if you are okay with going that slowly (not to avoid wind, afaik then you'd have to be unsafely close, but behind a truck you cannot annoy other people because they need to overtake the truck anyhow). The downside: on an average commute of like 20 minutes, that costs you probably like 2 minutes extra (since top speed is far above average speed usually). The upside: your fuel consumption (fuel burned = CO2 created) is cut nearly in half, at least for the highway part of the trip. No braking also means less particulate matter from brake wear; no shifting back means less partial combustion. Or so I've read.
The most efficient speed (afaik): as slow as your car allows (~1000 rpm) in the highest gear it has.
I hope it goes without saying, though, that one should prioritize safety (go with the flow; worse/more(?) accidents happen in high speed difference zones) over efficiency gains.