No need to wait, you really got it exactly right - a two-stroke engine where oil is mixed with the gas:

"RAY: What was unique about Mary Ann's car was it was a Saab. And from 1959, I think, to 1969, Saab made a two-stroke engine, which requires that the oil and the gas be mixed together. There's no oil in the crankcase.

These engines didn't smoke very much, because they were only about 40 horsepower. But, when the gas thief put this mixture of gas and oil into his Chevy or whatever he drove, the trail of smoke he left behind allowed the sheriff to follow him right home, and arrest him."

There have been three Car Talk Puzzlers since this one (I've been away) - shall I post them one at a time or all three?

OK, damn the productivity, full steam ahead!

1.
RAY: Draw a clock face on a piece of paper. Using Arabic numerals put the appropriate numbers at 12, 1, 2, 3 and so on.
Now, somewhere on the clock face, draft two lines. In doing so, you're going to divide the clock face into segments, which contain numbers.

TOM: Do the lines have to go from one edge of the clock face to another?

RAY: Yes. So, when you draw the lines, you will wind up with either three or four segments of clock face. If the lines intersect someplace, you will wind up with four sections. If they don't intersect, you will wind up with three sections.

The question is: Where do you draw the lines so that the sum of the numbers in each section is equal?


2.
RAY: It’s World War II, an RAF airfield north of London. A dimly lit Quonset hut filled with air crews has just returned from bombing runs over Germany.

The meeting opens with the chaplain leading the men in prayer for their lost comrades. He is followed by the flight operations chief, who begins the debriefing by asking the airmen, "From what direction were you attacked by the German fighter planes?"

Without hesitation or dissent, the reply was, "From above and behind."

The flight operations chief hastily scribbles the information on the back of top secret maps, and hands it to a junior officer with the instructions, "Get this information to the departing air crews. It may save their lives!"

As the officer turns to leave, from the inky shadows, a hand grasps his arm and he hears these words:

"Hold that order. The information you're about to give will lose lives rather than save them."

What did the guy from the inky shadows know that the flight operations chief didn't?


3.
RAY: While we were way up north this fall looking at the New England foliage, we visited our Chief Web Lackey, Doug Mayer. He said, "There's a road right near my house that runs directly north and south."

I said, "Yeah? Show me."

And Mayer says, "I can put my car on this road and point it north, and drive for a mile and when I'm done, I'm a mile south of where I started."

The question is very simple: How's he doing it?


The answer to the third one has not been posted yet.

No, the lines are straight.

Wild Card, here's a hint: the clock face numbers add up to 78; ergo, the three sections must each add up to 26.

I wish I knew; the answer to that one will be posted on Saturday afternoon, along with the next Puzzler.

I have a guess to the third riddle! I'm going to delve deep into smart aleck roots on this one.