Has upgraded Ferrari closed the gap?

The Circuit Gilles Villeneuve is unashamedly a power circuit, so if your Formula 1 engine isn't strong you don't stand much chance of being competitive in a grand prix here.

Knowing this, both the Ferrari and McLaren-Honda F1 squads have spent some of their precious development tokens and brought updated power units to the Canadian Grand Prix.

Ferrari has spent three tokens, which technical director James Allison said earlier this year would "buy you a combustion upgrade", which he translated into pistons, cams, cylinder heads and injectors - essentially the top end of the engine.

Though Ferrari naturally wouldn't reveal exactly what it has changed for this race, the fact both Sebastian Vettel's and Kimi Raikkonen's cars have been fitted with new internal combustion engines for this event means it's reasonable to assume this is where adjustments have been made.

The aim of course is to close the gap to Mercedes, which has produced the class-leading power unit under these V6 turbo hybrid regulations and continues to enjoy a significant grunt advantage over the rest of the grid.

So the big question is: has Ferrari's token spending worked?

Of course we've only had Friday practice to judge it on as yet, so neither Mercedes nor Ferrari will have run their engines at full potential just yet, but a pure pace analysis of the gap between the W06 and the SF15-T at this stage of each race weekend so far this season suggests Ferrari might have made a small gain.

Vettel lapped his Ferrari 0.316s slower than Lewis Hamilton's Mercedes on the faster tyre in practice two, which is the closest a Ferrari has managed to get at this stage of a 2015 race weekend.

If you examine the best sector times each driver managed in the session Hamilton should have been another tenth clear in the end, but the fact is he wasn't and Ferrari can take some encouragement from that.

Though we have seen nothing so far to suggest the Scuderia is suddenly going to be a contender for pole, it does look as though it has made enough of an improvement to at least guarantee a row-two lockout - on a circuit that in theory should make it more vulnerable to the likes of Merc customer Williams.

Beyond that, the deluge that created conditions for Hamilton's brush with the barrier at the hairpin and rendered everything bar the first 35 minutes of afternoon practice meaningless means it's difficult to get a good read on long-run pace.

The teams had to condense their programs in expectation of the bad weather, so the data is limited. However, both Ferraris and both Mercedes completed short race runs before the rain fell, and (allowing of course that fuel loads and engine settings will vary) these paint a potentially encouraging pattern for Ferrari.

Raikkonen completed the fastest run of the four, nearly a second faster than Nico Rosberg over a seven-lap average. Furthermore, he did this on the harder of the two tyre compounds.

Now, we know Raikkonen has produced extraordinary pace on the slower tyre in the past - witness his stunning middle stint in this year's Bahrain Grand Prix - but Pirelli calculates the average pace gap between the two compounds here at between 0.8 and 0.9s in favour of the super-soft (obviously), so it is not realistic to expect Raikkonen to actually be faster than both Mercedes drivers and team-mate Vettel on a harder tyre come Sunday's race.

This was probably something anomalous produced by evolving conditions, and the way certain drivers managed their tyres, just before the rain spoiled the party.

Nico Hulkenberg's Force India lapped 11th fastest overall in the session and the German was faster on the harder tyre than he was on the super-soft. This is not likely to be reality on Saturday.

The graph shows how the pace of the top four cars converged as the runs went on, and it's reasonable to expect that Mercedes will turn up the wick and be much more competitive in real race trim than it appeared on Friday.

Certainly that was Allison's conclusion. "It's hard to know what to make of today," he said.

Early signs for Ferrari are good © LAT

"Normally these free practice sessions have a sort of pattern and a rhythm to them; we all do more or less the same programmes week after week and we get to have a feel for where we stand based on that.

"But on a day like today, when the weather mucks things up and you can see the rain coming but you're not quite sure when it's going to come, people tend to work on slightly different programmes, and it makes it a little bit harder to judge.

"We think we went quite well today, but I also think these chaps [Mercedes] are probably hiding their light under a bushel a little, so we'll see."

The question mark for everyone is degradation. Track temperatures for the rest of the weekend are expected to be higher than the 31C we witnessed in second practice, and the washout on Friday afternoon means super-soft tyre data for this circuit is limited.

Pirelli reckons the soft tyre can go for 70 laps (the entire race distance), so it's reasonable to expect the super-soft to hold up reasonably well too.

Whether it is well enough to put the ultimate strategic choice agonisingly between one or two pitstops is unknown, but given this circuit has one of the shortest pitlanes on the calendar the penalty of making an extra stop will be greatly reduced.

If a two-stop race ends up being the strategic norm then Ferrari will have little chance of beating Mercedes here - providing Mercedes has some race pace in hand as expected.

The new Ferrari engine looks to be an improvement, but potentially only enough on such a power-sensitive track to keep the Scuderia standing still in the grand scheme of things.

WHAT OF McLAREN-HONDA?

The fact the next fastest cars were the Mercedes-powered Lotus and Williams machines suggests the three-pointed star still rules the roost when it comes to engine performance, despite not bringing performance upgrades to this race, while Renault-powered Red Bull and Toro Rosso have also slipped back slightly compared to recent races (though they too could potentially make a significant leap in qualifying trim).

But what of McLaren-Honda - the other marque to have spent tokens on an upgrade, believed to focus on the MGU-H energy recovery system?

Well, the team does not expect to fully realise the gains of this upgrade until the next race in Austria (where the cars will run at higher altitude) and so far the MP4-30 does look exposed on the Circuit Gilles Villeneuve - lagging behind all bar the Manor Marussias on pure pace.

PURE PACE RANKING

1. Mercedes 1m15.988s (Hamilton)
2. Ferrari 1m16.304s (Vettel)
3. Lotus 1m16.600s (Maldonado)
4. Williams 1m16.849s (Bottas)
5. Red Bull 1m17.092s (Kvyat)
6. Force India 1m17.120s (Hulkenberg)
7. Sauber 1m17.261s (Ericsson)
8. Toro Rosso 1m17.318s (Sainz)
9. McLaren 1m17.627s (Alonso)
10. Manor 1m19.531s (Merhi)

A problem getting out of second gear held Jenson Button back in the first free practice session, and he was only 18th fastest in FP2 with the new Honda unit - over half a second adrift of team-mate Fernando Alonso.

"I've got some things that aren't quite right at the moment," he said. "We'll sort that out for tomorrow and then I can tell you [whether the new engine is better].

'We're not running where we should be with the power unit, but tomorrow we will be.'

That's when everyone will turn the engines up to full qualifying mode. Only then will we see whether the upgraded Ferrari really is any closer to Mercedes here, and just how far Honda still has to go.