A hard day to get good efficiency
 

Today was a beautifully sunny spring 80 degree day.
When I hopped in my HCH for my daily commute, the FCD was still at 63.8 and 46 miles from where I parked last night but looked at the clock and it said 3:35PM.
I was running about 10 minutes late.
Looking at the front yard flagpole there was a strong wind, but there in the subdivision is hard to get a good directional fix.
Driving through town I realized in my haste forgot to reset my trip meter so decided to just let it increment without a reset.
While in town I noticed those little 3 inch construction marker flags were blowing with a N.E. wind, which meant a headwind.

Because of the time crunch I knew I'd have to abandon my usual 45MPH limit highway route and get onto the 70MPH 2-lane grassy-median freeway.

I could have jumped right onto it 2 miles from home but decided for more warm-up time and drove 5 more miles to the next closer entrance.

So on the freeway I went, accellerated to about 65-68MPH right lane traffic.
This stretch of road is plagued by 1-4 mile long uphill grades.
I noticed my FCD drop from 62, to 61 all the way down to about 58.5. :(
After about 5 miles I came behind a large truck, one of those that pull a smaller trailer that pulls another smaller trailer.
I noticed that he was also driving with load, and his truck slowed to around 55 at times, but never exceeded about 62MPH.
With the headwind we had it looked like all the trucks were slow & fighting it as well.

The blowing flags along the route still showed a strong headwind, enough to stand one of those huge 40' ones straight out.

So, I rode about 30 miles behind this truck in my coveted place at a safe distance of ~75 feet and noticed my FCD was now indeed increasing.

When I finally moved aside we were already in a 55MPH zone, I wished good luck & a safe trip to my trucker friend and parked it with 61.3MPG and 90 miles on the dial. And about 10 minutes early.
Not nearly as good as usual but cirtainly better than what could have been.

Why did my efficiency increase under such a headwind?
I would guess that I wasn't getting much drafting benefit at my safe distance but he was definetly a shield to the headwind and riding at a reduced speed.

Sometimes it is amazing what we can find to increase our MPG.
Any thoughts?