Perhaps you’ve seen reports this week saying Toyota “will” or may achieve a 10-percent improvement “goal” over the current-generation Prius’ 50 mpg combined EPA rating.

The notion that Toyota will try for a 55 mpg target was not actually said by Toyota, and these reports are the product of two inductive leaps by journalists: 1) that Toyota’s goal is 10 percent, and 2) that Toyota aims to hit it.

In fact, Toyota Managing Officer Satoshi Ogiso called 10 percent a “crazy number,” and said it would be harder than ever to hit this incremental gain as he had in a former role as head engineer for the Prius.

He otherwise gave nothing more than very hedged answers to probing questions by two journalists on Wednesday at Toyota’s Hybrid World Tour in Ypsilanti, Mich.

The context for the roughly 10-percent improvement goal speculation is based on the past trend from Toyota’s first Japanese-launched Prius in 1997 to generation two in 2003 to the present third-gen in 2009.

The inductive leap came after Ogiso referred to these previous incremental increases. His answer was in response to the classic scenario of a journalist – in this case from Forbes – asking a company to tell its secrets a few years in advance, and having the company say it cannot answer future product plans.

With laughter and humor as he gracefully played his traditional role in the age-old ritual, Ogiso deflected the pointed question, made reference to past benchmarks set, and essentially said, take a guess.

“Please ask something else,” Ogiso said at the end of his round-a-bout response to the laughter of a room full of journalists.

Then, several minutes later in the open Q&A sessions, Automotive News’ Mark Rechtin again asked Ogiso to spell out future plans, and again, a question was met with deflection.

“Americans like really big round numbers for their fuel economy. It’s a great marketing idea, it gets them very excited,” said Rechtin somewhat humorously prefacing his question.

“You’ve talked about vastly improved fuel economy,” Rechtin continued now getting to his specific question. “Are you willing to say the next generation Prius will get 60 mpg?”

Ogiso’s answer was a softball and humorous reply that mitigated the probing question with more allegory.

“Thank you so much for a difficult question to answer,” said Ogiso San. “Of course I love rounded numbers … ”

He went on to ask the reporters to recall that 50 mpg combined rating for the present Prius is a world record. He said also he is a runner for physical fitness, and can appreciate the challenge to human limitations in breaking a world record.

As an example, he mentioned the current 100-meter dash world record. This is presently owned by Usain Bolt at 9.58 seconds.

Ogiso followed this by saying that if the fourth-generation Prius exceeds 50 mpg, it would be on par with a shattering of the 100-meter dash record.

“It’s a world record. So from 50 – 55 improvement rating, 10 percent, that’s just equal to [saying] “He broke his record from 9.5 seconds to 8.5 seconds,” said Ogiso implicitly referring to his statements on past achievements made to the Forbes reporter. “It’s very hard, hard work to keep continuous pace from first generation to current generation and fourth generation.”

After painting that image, Ogiso San said “10 percent is a crazy number, but we will continue our challenge.”

And despite the old mantra that “past performance is not necessarily indicative of future performance,” most reporters ran with the imagery and said Toyota wants 10 percent next time.

Actually, Ogiso left it open whether the company would accept a lesser increase, and undoubtedly it would be happy if it manages to pull off even more from the next-generation parallel hybrid that has been suggested will be launched some time around 2015.

Bottom line: Ogiso said Toyota has embraced the goal for improvement, expects to beat its past record, but what it actually does we’ll have to wait and see.