The EPS Graflight V-8 has demonstrated the highest fuel efficiency of any general aviation engine. This is illustrated in Figure 1 which shows the hourly fuel cost as a function of horsepower for 10 different general aviation engines. These engines fit into three distinct categories.
- Avgas engines, as shown by the solid and dashed black curves which require the abrupt increase in fuel consumption at 262.5 horsepower in order to prevent destructive detonation and pre-ignition.
- Turboprop engines, as shown by the single dotted black curve.
- Diesel engines, as shown in the remaining 7 colored curves.
The diesel engines show considerably better fuel efficiency than the other two categories. The EPS Graflight V-8 is the best of the best as shown in the solid blue curve which demonstrates 15% better fuel efficiency than the 6 other diesels. This blue curve is the actual measured fuel efficiency of the Graflight V-8 which maintains its leadership over the competition throughout a remarkably wide operating range from 30 to 380 horsepower.
As an example of what this data means to the end user it is worth comparing the Continental TSIO-550-E Avgas engine to the EPS Graflight V-8 diesel operating at 75% of the full 350 horsepower which is 262 horsepower. At this power the Continental hourly fuel cost is $114/hr but the EPS Graflight V-8 is only $63/hr for a $51/hr savings.
Figure 2 shows the hourly fuel costs chart for the higher fuel costs found in Germany. At 75% power of 262 horsepower the Continental hourly fuel cost is $251/hr but the EPS Graflight V-8 is only $126/hr for a $125/hr savings which is cutting the fuel costs in half.
Figure 3 shows the hourly fuel flow in gallons per hour for 10 different general aviation engines.
Figure 4 shows the hourly fuel flow in pounds per hour for 10 different general aviation engines.