With the summer driving season in full swing and oil prices on the rise, locking in low gasoline prices through a buying club sure sounds like a wise investment. But making the right bet on the direction of fuel prices is hard enough for airlines and professional commodities traders, let alone the average driver.

The gas-buying club pitch is straightforward: Prepurchase fuel at today s prices and then redeem it for a profit in the months ahead when -- presumably -- gas prices have gone up. Clubs open to consumers include MoreGallons.com, Petrofix and First Fuel Banks, among others.

The problem, of course, is that there's no guarantee that you will buy low and sell high. "It amounts to trading in gasoline futures," explains James Brock, a professor of economics at Miami University in Oxford, Ohio. "It s a hard game to play and come out ahead in."

Although crude oil futures and gasoline prices both hit 2009 highs this week, the average going rate for a gallon of regular unleaded stands at $2.45 nationwide, according to AAA. True, that s up 40 cents from last month, but still a full $1.49, or 38%, cheaper than last year. And although a barrel of crude fetches around $65 today, that's a far cry from the nearly $150 it claimed in July 2008.

Read our story about fuel co-ops here

See our story, "Is Oil Spent or About to Geyser?

Here s how these programs work. Details vary from club to club, but generally you prepurchase fuel by the gallon, locking in the current market price plus a fee of, say, six to 10 cents a gallon. (Contracts can range from just a few months to several years.) When you buy fuel at the pump, the program usually reimburses you for whatever premium you paid, depleting credits from your account. For example, at First Fuel Banks, a club based in St. Cloud, Minn., members currently pay $2.68 per gallon to lock in prices for an unlimited time, and then use a special debit card at the company s gas stations. There s also a $1 lifetime membership fee.

Further complicating matters is that any possible savings vary from program to program. So if you must trade in gas futures, do your basic due diligence. It's imperative that consumers crunch the numbers, asses their driving habits, check the fees, and make sure they're dealing with a reputable program in order to have a chance at coming out ahead. Here are some keys to consider.

Forecast fuel prices

The biggest caveat is that no one has a crystal ball. Consumers who took advantage of Chrysler s 2008 "Let s Refuel America" program, which capped prices at $2.99 a gallon for three years, are losing out on that investment this year. Just because gasoline prices are going up now doesn t mean that the trend will continue, says Brock. Indeed, the Energy Information Administration expects prices to average $2.21 per gallon through September -- but just $2.12 for all of 2009. Consumers who buy in at too high a price face a dilemma: They can either overpay for gas now or let their accounts sit idle, accruing maintenance fees, while waiting for prices to rise.

Compare potential savings

Companies offering fixed-price fuel programs have to make a profit somehow, says Samples. That could include membership fees, profit built into the per-gallon rate and service surcharges -- or some combination of the three. The longer the lock-in period, the higher the price per gallon. Factor that in to calculate how much per gallon you re really saving compared with current prices.

Assess driving habits

Locking in a fuel price rarely makes sense for consumers who don t drive frequently, says Naveen Agarwal, CEO of Pricelock, which administrates fuel-price protection programs. (Pricelock developed the Chrysler program.) Bigger prepurchases (like buying in bulk) usually equate to bigger savings. The fewer gallons you prepurchase, the less likely it is that those savings will offset your program's fees.

Check program reputations

There can be substantial risk with a company that s popped out of the woodwork, says Samples. If they declare bankruptcy, you re at the back of the line to get your money back. Check for complaints with the Better Business Bureau -- and read the contract carefully to find out your rights. If the program goes kaput, so too can your cash.