Running down the road in this Chevrolet Suburban will cost you about 30 cents a mile for fuel alone, more than four times the cost of operating a Toyota Prius.

Fuel prices have been riding the proverbial roller-coaster in recent months and that has more American motorists than ever focused on finding the most mileage-minded vehicles available that can fit their needs.

While it’s hard to find a manufacturer that hasn’t been pushing for improved fuel economy, there’s still a big gap between brands, according to a new study that finds the typical GMC product has, on average, the most costly products to operate in terms of fuel costs per mile. Parent General Motors, in fact, produces six of the ten most costly vehicles, according to a new study by tracking service GasBuddy.com.

At the other extreme, Honda was the cheapest brand, at a cost of just 12.8 cents per mile compared to 21.2 cents for GMC.

Potential buyers should take caution before steering clear of any brand, however, and instead do an apples-to-apples comparison of similar products, cautioned GasBuddy’s senior analyst Patrick DeHaan, who noted, the brand-based costs “depend upon the manufacturer’s line-up.

“Honda puts out quite a few high-mileage models,” DeHann told TheDetroitBureau.com, while, “GMC is weighted to heavy-duty models which aren’t going to get as good fuel economy.”

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On the whole, the industry has made major strides in mileage, a separate study by the University of Michigan Transportation Research Institute, or UMTRI, showing that fuel economy, on the whole has climbed to record levels in recent months, and with only a rare exception continues to climb each month.

Even big pickups like the GMC Sierra are getting better mileage than ever before – though GasBuddy analysts DeHaan stressed that the biggest gains are coming on the passenger car side of the market. At the average national price for fuel this month, the tracking service estimated the Toyota Prius cost just 7.2 cents per mile to operate. That was less than a quarter of what it would take to fuel the big Chevrolet Suburban. And for two drivers putting on 1,500 miles behind the wheel, that would add up to a difference of $310.

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The new GasBuddy study did not, however, do an apples-to-apples comparison, such as pitting a midsize Toyota Camry against, say, a Ford Fusion or Nissan Altima, or a Chevrolet Silverado pickup against a Toyota Tundra or Ford F-150.

But on a brand level, the truck-focused GMC was clearly the most expensive when it came to per-mile fuel costs at 21.2 cents, followed by Cadillac at 19.0 cents, Mercedes-Benz at 18.6 cents, Jeep at 18.5 cents a mile, and Jaguar at 18.4 cents.

While Honda was cheapest, at 12.8 cents, Kia was close behind at 12.9 cents per mile, followed by Hyundai, Volkswagen, Mazda, Subaru, Mitsubishi and Toyota.

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