I had three questions after three months with my XC60 T8 PHEV.  

**First: is motorway driving actually cheaper than city driving?**   
That's where I started, and on electric power alone the answer surprised me: 21.5 kWh/100km on motorways vs 22.8 kWh/100km in town.   
The steady highway run, the one that feels thirsty in a petrol car, is the more efficient one when the battery is involved.   
But that's only half the answer, because a PHEV has two energy sources. The real number changes dramatically once petrol enters the equation. Which is where the second question took me.

**Second: what's this actually costing me (both fuel types)?**   
A PHEV has two energy sources, and they're not equal.   
On pure electric at home rates (€0.34/kWh, actual Dutch contract), a trip runs about €0.07–0.08/km.  
But the moment the petrol engine kicks in, the same distance costs \~€0.50/km.   
That's roughly 6× more.   
  
The API gives you trip-level consumption for both electricity and petrol.  
  
So, I wired it to real prices: my actual €/kWh from home charging, my actual €/L from pump receipts, split per trip, divided by distance.   
No averages, no estimates.   
The €/km number doesn't tell the whole story until you see the fuel mix behind it & that's where the car tells you what you're really spending.

**Third: can I predict the next trip before I start?**   
Built a forecasting model on the trip history. This was the most fun one.   
It guesses my consumption before I leave the driveway.  
  
Is it always right? No.   
Is it right enough to be useful? Yes  
  
and it will keep getting better. with each trip made.

  
*This is just the surface of the rabbithole, LOL. Then i had more questions.*

Along the way my curiosity pulled me further:

* What road types am I driving on?
* Can the car learn my route families without me labelling anything? 
* What's the efficiency difference on a road-by-road level? 

  
A weekend project, then another, then another.   
  
The GPX export gives speed and bearing at every trackpoint.  Which turns out to be enough to start measuring how smooth a drive really is. That's a later build **or** maybe the dev-gods can make my life easy by adding G-force data to the GPX export someday. *wink* *Hint hint*.

I should also attribute the 2 specific git repos that help me build this:  
google-research/timesfm  
google-research/tabfm

They really helped fill the gaps. I am not a developer, just someone with a hermes agent, time and curiosity.

If I can wire this together, anyone with curiosity and an API key can.

All of this runs on the Aximote API. I pay for the Pro licence, and honestly, it's worth every cent.  
  
The endpoints carry more detail than the official app shows now(*it could show more, you never know*), and the team has been responsive whenever I've hit a question. Just good data and the right questions.

  
So here is me peeping out of my rabbithole, asking:   
What questions did your car make you ask?   
Anyone else pulling Aximote data into their own stack, and what did you find?





200 trips in my XC60: here's what I wanted to know, and what the Aximote API let me answer