Broke the 50mpg barrier at the MPG Rally!

[KJSatz]

Did you use 5th all the way from "25-35" to 55, or what combination of gears did you use?

As for staying over 40mpg, most of my driving is highway. I have done a couple hundred miles of city driving this tank, and it seems like I've been having success according to the scangauge (which I have not adjusted...).

[superchow]

If the speed was down below 35, then I'd bump start in 5th, shift into 4th and accelerate back above 35. Then back to 5th gear all the way to 55.

Here's a graph I found on Temple of VTEC Asia in the i-VTEC implementation on the K20A engine. Yes, it has a DOHC vs SOHC layout, and 2.0 liters vs 1.8 in our cars, but I believe the general implementation of the different "phases" are similar. (The torque graph is uncannily similar...)



Here the link to the whole article: Honda's K20A Engine

Most interesting to me was the probable fact that low revs/high load (zone "3" on the graph) in this car is counterproductive. I'm estimating the switchover from "Low cam" to "High-speed cam" at about 3500 rpm. So, in conclusion: Loads from 15-20% to 50-55% and revs from 1500-2000 rpm to 3000 rpm should keep the engine in the "lean-burn" range, zone "1". (Idling will also keep the engine in lean burn, which may be worth an experiment in the future comparing different driving methods.)

[KJSatz]

Well I am not completely sure about this information. Our engine, R18, does not have lean burn. It's pretty difficult to get meaningful acceleration at LOD 50%. I'll do some experiments trying LOD around 60 and see if it works alright.