Labor Day opportunities

Thanks to "F8L", we have a 'Top 20' list with simples rules:

• 500 mile minimum distance
• photo of tripmeter with: miles, MPG, and average speed

With Labor Day coming up, many will have an opportunity to provides new updates to the spreadsheet:


I'm suggesting those who advocate these techniques use this weekend to fill out the higher speed end of the chart:

1. Super Highway Mode
2. Ignition Timing
3. P & G
4. W & S
5. Straight gas
6. Tire inflation pressures
7. Tire makes and models

In a perfect world, use one tank for the weekend so the starting and ending altitudes remain the same. If not, share the starting and stopping altitudes and weather along the route (i.e., head, cross and tail winds.) If two tanks are over 500 miles each way, we can average the two.

This weekend provides an excellent opportunity for those who subscribe to these driving techniques to get on the Top 20 list and a spreadsheet entry. But it doesn't have to be this weekend. There are three day holidays in October, two in November, two in December, one in January, and one in February. All opportunities for excellence.

GOOD LUCK!
Bob Wilson

 

Your numbers are consistent with my measurements:

• 80 mph -> 40 MPG in 62F with defroster (5.9 l/100 km @128 kph 17 C with defroster)
• 75 mph -> 44 MPG in 82-86F (5.35 l/100 km @120 kph 28-29 C)

Speed is the primary fuel consumption determinant. But there are a set of minor vehicle changes that help: increase tyre pressure; lubricants including transmission oil and; aerodynamic mods. Individually, these have only small effects, a couple of percent each, that collected can give measurable improvements.

If we do a high-speed, weekend trip, I'm thinking about using some warm-weather, front grill inlet reducers. At high-speed, the car still has excess cooling air, aerodynamic drag. My thinking is encroaching from the edges, reducing the 'spill air' out the edges would give another, incremental improvement. It is based upon A-B testing of a conformal, air block and recessed air block.

There was a solid 2% drag reduction using the conformal block over the recessed block. I've long suspects that excess cooling air still spills out the edges of the air inlet. So in theory, corner blocks that have a smooth curve into the inner grill should still provide more than enough cooling air while reducing aerodynamic drag.

In theory, a pair of segmented, air dams in the corners could open and close based upon coolant temperature. Opening when the temperature reaches 90C and closing at 80C. The ideal would be to adjust the air inlet opening to sustain an 87-89C target coolant temperature.

Bob Wilson

 

If I need angst, I go to work. <GRINS>

Driving should be fun and until we have "Johnny Cab" super-cruise control, as calm an adventure as possible.

Bob Wilson

 

Not to worry, perhaps you remember these charts:

There are a couple of 'outliers' at 50 mph that remain curious. I'm not too surprised at the variability in the 15-30 mph region as warm-up costs can play a significant part in this region. This is where judicious application of PiP charge to cover warm-up costs would have a significant effect.

Use the PiP charge for two miles of the "cold soak" warm-up and then one mile for each subsequent trip. Thereafter, the slower speeds on a warmed up ICE will pay great dividends. In a perfect world, this would be automated to provide traction battery assist up to 60C and then preserve the charge thereafter for the subsequent trips.

There is another interesting chart:

What this suggests is an optimum, daily mileage in the 50-90 miles per day works best for our ZVW30. Shorter daily mileage pays the warm-up cost . . . it can be minimized but not evaded. But the 90-135 mile range dip . . . still has me curious.

Recently I completed a 1,000 mile tank. It turns out the secret was revealed in this 9/14/2009 post:

Notice:

• 5 minutes warm-up
• 1 minute transition
• 5 minutes of 100 MPG

The marathon made sure each trip was 60 minutes long so the warm-up cost were diluted 10-to-1. Remember, a marathon stunt is not designed to get anywhere, just demonstrate the characteristics of the car.

Bob Wilson