Right, low speed helps. Basically top gear at 2500 rpm (with a pipey little motor that's cammed to go 7500 rpm like a Miata). The hard thing is finding a road that is long enough to go that slow without any starting or stopping. I have another car that I practiced hypermiling techniques during my daily commute, taking low-speed roads rather than the freeway. Was watching the output of the mass airflow sensor and figured out the most efficient way to accelerate. And doing a lot of coasting with the engine off. I was only able to achieve the same gas mileage I could get on a long, non-stop 65mph freeway trip. Back to my original point, to get 38 MPG with a Miata takes going about 40 MPH and never stopping. It can be done, just not any situation that I've been in. As always, YMMV :) Cheerful regards, Bob On Fri, Oct 17, 2014, at 08:49 PM, RussellMc wrote: > On 18 October 2014 15:37, Bob Blick wrote: >=20 > > That's some serious hypermiling for a Miata. >=20 >=20 > (I know you know that ) Aerodynamic losses predominate at more than a > lope and increase with the cube of air speed, so low speed can help > heaps. > You lose one power of V when considering energy per distance, as t > increases inversely with V but its still a square law with respect to > energy per distance. >=20 > FWIW wind power loss =3D 0.6 k A V^3 at sealevel where K is drag > coefficient > =3D 1 for a flat plate and somewhat less with care and luck. >=20 > Leading factor of 0.6 works for SI / ISO units (=3D 0.5 x air_density = in > compatible units =3D 1.2 kg/m^3 for air at sea level). >=20 --=20 http://www.fastmail.fm - Send your email first class --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .