Renault e.dams driver Buemi holds a one-point lead over di Grassi heading into this weekend's deciding double-header in London.
Di Grassi fears the championship's Fanboost voting system can be manipulated but Buemi said it would not matter if one of the protagonists received a boost and the other did not.
He pointed to the rule change that stops drivers claiming three points for fastest lap if they set that time using Fanboost, as Nelson Piquet Jr did last season when he defeated Buemi by one point in the inaugural campaign.
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"It's less concerning not to have it," Buemi told Autosport. "I'm not going to blame it on Fanboost if I lose.
"Last year I clearly lost the championship with the Fanboost because you could score fastest lap with it, so I have lost it through that.
"I think it's a great idea but I'm not a big fan of how it's working.
"It's a lot less helpful than last year, it's less power and it stays on for less time.
"Last year you were certain to overtake but this year you're not sure.
"If it was like last year I would have been concerned very much, but now I don't really care."
In addition to the possibility of one driver getting Fanboost over the other, the title rivals have also expressed concern over the championship's qualifying group system.
Last year's London race featured a wet track for parts of qualifying, handing some of the randomly drawn groups an advantage because the track dried throughout the session.
Di Grassi admitted he did not believe the rulemakers should change the Fanboost regulations just for the season finale, and Buemi said even though the weather is a frustrating variable that philosophy should extend to the qualifying system as well.
"You can't adapt the rules when you want," he said .
"If you start and it's wet, then it's shit and you're going to be unlucky.
"You shouldn't change the regulations because what happens next year? Where is the line?
"If I'm in a wet qualifying and he's in the dry, I'll be pissed off but that's just luck.
"I was winning Le Mans and we lost it on the last lap. That's motorsport."
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