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g/kwh

PostPosted: Thu Jun 27, 2013 6:08 pm
by superandy411
Is there a way to find out a MPG or L/100km for fuel economy because i dont exaclty understand the whole g/kw calculation as im from Canada.

If theres a way to convert it please share :)

Re: g/kwh

PostPosted: Thu Jun 27, 2013 6:20 pm
by Kubboz
No, there is not. To get MPG or l/100km, you need to have the whole car.

Re: g/kwh

PostPosted: Thu Jun 27, 2013 11:28 pm
by TheTom
The l/100km or MPG depends not only on the engine, but also on the car's weight and aerodynamics. If, for instance, you put a 1.2L I4 into a Smart, it'll be much more economical than if you put it in something like an Audi A6 because the Smart is smaller and lighter.

Re: g/kwh

PostPosted: Fri Jun 28, 2013 3:38 am
by superandy411
Oh alright. Yeah i kinda figured that might have something to do with it.

So when the car is complete ill have all the stats? Sounds good to me.

One question though would be how do I know what is considered good for g/kwh

like under 400g? under 300g? Whats atleast average.

Re: g/kwh

PostPosted: Fri Jun 28, 2013 7:13 pm
by Killrob
That very much depends on what time period you're in. In the 1950s a 600g/kWh engine is deemed efficient, while in 2013 a <300 g/kWh engine is pretty efficient.

Re: g/kwh

PostPosted: Tue Jul 23, 2013 9:14 am
by Snowmen
I'm a bit late but the whole g/kwh thing is called "Brake specific fuel consumption". Here's the wikipedia article about it: http://en.wikipedia.org/wiki/Brake_spec ... onsumption There's a part which lists some engines and their brake specific fuel consumption. If you want some guideline, a Ford Ecoboost Engine has a BSFC of 245 g/kwh and a modern diesel engine has one under 200 g/kwh. That might seem impossible to reach but it's not! This is the BSFC at it's lowest while the stats sheet lists efficiency as some sort of average. Look at the graph and see what's the lowest BSFC your engine achieve (usually near the peak torque or the start of the peak if it's pretty flat). If you have something around 250 g/kwh at that point and around 300 g/kwh as a total, that's fairly good for a normal engine. An economic engine can get as low as 225 g/kwh at the torque peak if you tweak it.

Re: g/kwh

PostPosted: Tue Jul 23, 2013 4:41 pm
by Kubboz
Yeah, Automation's fuel consumption is taken as the average of consumption in 1500-2500-ish RPM range, thus it's more useful, as you don't always travel on the most efficient conditions.