SAN ANTONIO -

Gas prices have risen 33 days straight for a steep 40-cent jump in the past month.

It's too steep for Sylvia Wallace.

"Isn't that ludicrous? Absolutely inexcusable behavior," she said while watching the numbers on the pump roll. "It's way too doggone much money. This is Texas. How are we supposed to get our groceries (when gas is) at $3.99?"

She was putting $3.99 diesel in her farm truck.

Prices varied significantly around the area Tuesday. Some of the highest was $3.79 on I-10 East at the FM 1518 exit.

The average for regular was $3.52 Tuesday, up 16 cents in the past week and up 40 cents in the past month.

Arrington Bonds was putting her last $6 into her gas tank.

"It's crazy, man," she said. "Gas is $3.55. That's not going to get me nothing, but we're going to try."

$6 got her 1.6 gallons of gas.

Prices typically surge as refineries switch to summer blends.  While many consumers are puzzled  about the fast and steep rise,  industry analysts say higher crude prices, increased global consumption and market speculation are all factors.

For drivers filling up, it's become a game of "guess how much my fill-up will cost."

"Probably get close to $90," said Chris Gardner as he was fueling his company pickup.

He was low. The pump cut off at $100.

For a list of recent stories Marilyn Moritz has done, click here.