INDYCAR: Honda Focused On Fuel Efficiency For Indy

IndyCar

INDYCAR: Honda Focused On Fuel Efficiency For Indy

If Monday's Texas oval test told us anything, it's that Honda has plenty of power, but can it challenge Chevy's series-leading fuel efficiency at Indy?

Marshall Pruett | Posted May 08, 2012

Having the most powerful engine in the series isn't always a positive thing, as Honda has found. With Chevy's top drivers able to go 1-2 laps longer on a tank, bridging that gap for Indy is a must. (Photo: Marshall Pruett)

Getting to the finish line first at Indy has rarely been achieved by the simply bringing the most powerful engine to the 500-mile race, and this year's event is no different.

The exceptions to the rule are well-known. Mercedes used its zillion-hp pushrod V8 to run circles around the competition in 1994, streaking into the distance between pit stops, but that kind of advantage doesn't exist in 2012. Using identical Dallara DW12 chassis, the power required to achieve a two or three mph advantage comes with an inherent penalty which engine manufacturers dedicate thousands of hours to overcome, and those differences in fuel economy can have a major influence in how the Indy 500 is won or lost.

With new turbocharged engines, single- and twin-turbo layouts, direct-injection and a host of variables that give the powerplants from Chevrolet, Honda and Lotus different performance characteristics, the quest for outright fuel efficiency at the Speedway has received as much attention—and possibly more—than any other tuning category in the months leading up to this year's race.

The recent equalization of turbocharger performance between the single and twin configuration has shifted the horsepower war in Honda’s favor, but as what cost? Through the first three rounds of the 2012 season, its Chevy-powered rivals held a noticeable fuel economy advantage, and at the most recent round in Brazil, where Honda had the larger cold-side turbo housing cover installed on its engines, its miles-per-gallon figures worsened.

Now, with practice just days away from beginning at the Brickyard, the biggest task for Honda Performance Development is to claw back some of the fuel mileage it will need to keep touch with Chevy’s best drivers on May 27th.

“We’re not happy with where we’re at,” HPD Technical Director Roger Griffiths told SPEED.com. “It's interesting. I agree that I think GM right now has an advantage but it doesn't appear to be across the board. And I think that it's interesting to ask why it’s only Will Power that can get that mileage? And then at Sao Paolo it was Will and Ryan Hunter-Reay that got it. But it doesn't appear to be across the board. Now, I doubt they’re running different engine specs and different calibration so what else is different? But it's something that we've noted. For sure, we’re working to close that gap.”

Power, like Honda-powered Dario Franchitti and Scott Dixon, is renowned for his ability to go fast while saving fuel, but Griffiths will be relying on a lot more than his drivers to stretch the 18.5 gallons of fuel each car carries.

“Improving fuel efficiency is just hard work,” he said. “Fuel mileage can come from any number of areas. It can come directly from the engine, how it’s calibrated, how it's run. It can come from reducing the rolling friction of the car, you know, internals or gearbox or wherever it can come from. From reducing the aerodynamic drag of the car. The driver himself can have a great impact on that. I think one of the issues Honda’s had, because the drivability of the Chevy engine has been pretty good, the Honda drivers are having to do things that are not economical in the style driving, just to keep up. And that sort of hurts us. So we need to address the issue on many fronts.

“There isn't just one knob you can turn to say, okay, well, this is it. Sure, you can lean the engine out; at that point you start losing performance. So if you can’t keep up you have to run a richer mixture and that reduces your fuel mileage. So it's not just a simple thing, it's not just ‘run lean.’ Efficiency has to be addressed in many different areas, and it's not just the engine.”

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