There has been a lot of speculation over Ferrari's F1 power unit during the off-season, with the team rumoured to be bringing an extra 30bhp.
This would stem from reliability upgrades only, as teams are restricted from making any big improvement on performance as a cost-cutting measure.
While Team Principal Frederic Vasseur has been quick to rubbish any claims of extra horsepower, Red Bull team boss Christian Horner is wary of any upgrades that could be made following Ferrari's poor reliability in 2022.
"The the engines are homologated, so theoretically there shouldn't be big horsepower gains," Horner said in an interview with Auto Motor und Sport.
"Also the fuel is homologated, so any reports of new fuels shouldn't be be permitted."
"Ferrari had some reliability issues last year, so if they've managed to address that and through that been able to turn up their power, inevitably, they will see some form of progress now."
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No significant reliability problems for Red Bull
Horner said Red Bull needs to be "mindful" of Ferrari's ability to gain performance just from running the engine in higher settings, after they needed to reduce the power following their reliability problems last year.
He continued: "It's a lot [of potential horsepower], so we have to be mindful of that. We saw them turn down the power after their failures last year. So we know they have the ability within their engine to turn it up more."
By contrast Red Bull did not experience as many reliability-related problems following the first few races, but Horner confessed that it was not enough for them to reduce the power output.
Horner added: "We had some small reliability issues, but nothing to the magnitude of Ferrari."