u/Splatage_NZ

Hi Reddit,

Warning app promotion ahead...

Going by my numbers I’m not a hypermiler, just someone who hates wasting increasingly expensive fuel

Over the years I have learned a lot from following hypermilers and trying some of the safer techniques. I appreciate getting a bit further on each tank, but really the science of it all fascinates me

Earlier in the year  I purchased a bluetooth OBD adapter to chase an engine code on my daughters car. Probably a mistake, but the bug bit and sent me down a rabbit hole of analyzing data

I have been able to dial my car and driving a lot better, and the results are surprising to me. 
For example I have used pulse and glide a fair bit, however I have been able to show that for my car - a Subaru Legacy with a CVT trans - steady state is consistently better
There are speeds "islands"where mileage peaks, one around 80kph and another around 100kph - its not a linear relationship at all
The other really significant  finding was how dramatic a difference coasting makes when approaching speed changes and stops. Logically this make perfect sense. The momentum in my car would carry it for the good part of a kilometer from 100kph on the flat

I started wondering whether you could work out when it actually makes sense to lift off — not just “coast more”, but when to coast so you don’t slow down too early, end up having to accelerate again, or annoy everyone behind you

So I’ve been building an Android app called EcoDrive

The idea is that it learns how your actual car behaves — how quickly it loses speed, how well it carries momentum etc. It uses the road data ahead and shows you how far you would coast. Worked fantastic on level roads...I got a bit carried away (again) and have built a custom map set that includes road slope. At the moment I’ve only processed and released for NZ, Australia and Great Britain, mostly because that’s where the friends/family testing live. If there’s enough interest elsewhere I can add more, although they take a silly long time to process

Once my local map set was done for testing I realized estimating engine power, BSFC and cruise efficiency were easy to infer from OBD data
An OBD adapter isn’t really required, without one you still get the core coast/glide prediction. The OBD data lets it learn and analyse a lot more

I’ve finally got it onto the Play Store and I’m at the stage where I really need people who actually think about this stuff to tell me what I’ve got right, what I’ve got completely wrong, and what would make it genuinely useful

I figured r/hypermiling was probably one of the better places to ask

Happy to explain how any of it works if anyone’s interested. And critique is very welcome — I’d much rather hear “this is crap because…” now than spend more time creating something crap!

If anyone wants to have a play the link is: here