"Kitna Deti Hai" (How much it gives) is a classic question but an equally important question is
"Kitna leti hai" (How much it takes).
Answers to all such things are our threads like Official Team-BHP reviews, Ownership reviews, Long term ownership reviews, What car, etc., They all serve a common objective i.e. to help potential buyers with data/information to decide on their next vehicle. When we read comments or queries in such threads we may find some of them qualitative while some other are quantitative. The answers to qualitative queries are a matter of experience and may well be subjective. The answers to quantitative queries can be clarified with Data/Stats. For example, questions like "How old is old" or "How old is new" (although subjective) can be reasonably answered using statistics with confidence intervals on most likely probability.
All we need here is Data and I believe some of us have a habit of logging vehicle performance. Such data can be extremely useful if shared, studied and compared. In this direction, shall we have a dedicated thread of ownership data logs.
Just logging and monitoring the vitals can reveal a lot of information about your vehicle. To start with, I would like to share my vehicle log. It is a Vitara Brezza, Aug 2017. It has done 39000 km on the Odo and no major maintenance so far.
The fuel economy is meticulously tracked on a Full tank to Full tank basis, so all those data point in the above chart are averages over ranges of 800+ km. Also these are for mixed usage: city+highway+AC always on+idling.
Here are my observations.
Q: How long is running in ?
A: Definitely more than 20k
Q: How much new vehicle performance increases with Age ?
A: 10-12%
Q: Does synthetic oil gives better economy ?
A: Yes
Q: How different is the highway mileage from mean ?
A: Maximum 21 km/l vs the mean 19km/l
Q: What is the effect of mountainous/high altitude terrain on fuel economy ?
A: The mileage dips to 14-15 kmpl
Q: How old is new ?
A: Any car below 40k is a Virgin, Good news for all guys doing lateral upgrade, you are super smart. Somebody is doing the running in for you and you taste the cream at half the price.
Will keep updating my logs. I believe, like minded petrol heads would be also logging similar data. If you can share them, it would be of immense help to the community.