Mercedes AMG F1 W04

[kooleracer]

It was certainly not only fuel holding Rosberg back at Bahrain, clearly struggling with the tyres. How much of the 1.3 seconds would go to tyre issues and to fuel is everybody's guess, but judging that when temperatures dropped right at the moment Hamilton suddenly found pace, makes me believe the bigger issue was getting the tyres into the window.

I can absolutely believe that at that point they had to put in so much extra fuel. But that was then. We are several months further now; surely they would have reduced the bulk of the deficit towards the other teams by now?

I think the fact that lewis pitted and fitted hard tyres with less fuel, has more impact then the temp dropping 2 degrees. Hamilton went from option to option and then went to prime. With less fuel and new tyres any car would feel different. The feeling of new rubber and a lighter car explains resurgence more then 2 degrees drop because it was still hot compared to other races. The strategy for lewis worked perfectly. Doing 2 short stints and 1 long one the harder tyres with less fuel is the perfect strategy. Mediums are quicker so you will lose less time and the hard tyres can go longer en is more durable because during stint 3 Lewis had less fuel onboard.

But maybe during the season Ted Kravtiz or some one can ask Ross.

[turbof1]

It was certainly not only fuel holding Rosberg back at Bahrain, clearly struggling with the tyres. How much of the 1.3 seconds would go to tyre issues and to fuel is everybody's guess, but judging that when temperatures dropped right at the moment Hamilton suddenly found pace, makes me believe the bigger issue was getting the tyres into the window.

I can absolutely believe that at that point they had to put in so much extra fuel. But that was then. We are several months further now; surely they would have reduced the bulk of the deficit towards the other teams by now?

I think the fact that lewis pitted and fitted hard tyres with less fuel, has more impact then the temp dropping 2 degrees. Hamilton went from option to option and then went to prime. With less fuel and new tyres any car would feel different. The feeling of new rubber and a lighter car explains resurgence more then 2 degrees drop because it was still hot compared to other races. The strategy for lewis worked perfectly. Doing 2 short stints and 1 long one the harder tyres with less fuel is the perfect strategy. Mediums are quicker so you will lose less time and the hard tyres can go longer en is more durable because during stint 3 Lewis had less fuel onboard.

But maybe during the season Ted Kravtiz or some one can ask Ross.

Except that most people on 2 stops were on hards in their final stint, the effects you described counts for them all, yet it brought clearly the most improvement for Hamilton (everybody improved, but Hamilton improved by so much he went from worse to better compared to most others). He would be, at that point, still slightly above average fuel load if he really had to bring 15kg more along.
Definitely the harder tyres worked better for Mercedes though. Mind that Rosberg never got the same boost as Hamilton did; I suspect that a small setup difference would explain that. These cars work in such small windows that 2 degree celcius could turn the car around, if you have the setup to match it.

[kooleracer]

It was certainly not only fuel holding Rosberg back at Bahrain, clearly struggling with the tyres. How much of the 1.3 seconds would go to tyre issues and to fuel is everybody's guess, but judging that when temperatures dropped right at the moment Hamilton suddenly found pace, makes me believe the bigger issue was getting the tyres into the window.

I can absolutely believe that at that point they had to put in so much extra fuel. But that was then. We are several months further now; surely they would have reduced the bulk of the deficit towards the other teams by now?

I think the fact that lewis pitted and fitted hard tyres with less fuel, has more impact then the temp dropping 2 degrees. Hamilton went from option to option and then went to prime. With less fuel and new tyres any car would feel different. The feeling of new rubber and a lighter car explains resurgence more then 2 degrees drop because it was still hot compared to other races. The strategy for lewis worked perfectly. Doing 2 short stints and 1 long one the harder tyres with less fuel is the perfect strategy. Mediums are quicker so you will lose less time and the hard tyres can go longer en is more durable because during stint 3 Lewis had less fuel onboard.

But maybe during the season Ted Kravtiz or some one can ask Ross.

Except that most people on 2 stops were on hards in their final stint, the effects you described counts for them all, yet it brought clearly the most improvement for Hamilton (everybody improved, but Hamilton improved by so much he went from worse to better compared to most others). He would be, at that point, still slightly above average fuel load if he really had to bring 15kg more along.
Definitely the harder tyres worked better for Mercedes though. Mind that Rosberg never got the same boost as Hamilton did; I suspect that a small setup difference would explain that. These cars work in such small windows that 2 degree celcius could turn the car around, if you have the setup to match it.

How do you explain the quali pace? If there troubles are temperature related? So Merc has always been blessed with good condition on saturday? And remarkably every Sunday the condition were bad because the temp was 1 or 2 degrees higher each race? I really don't buy that.

[BlackMercedes]

It can not be entirely heat related as to why the car is so slow in the race, under fuelling the car in quali will show it's pace due to the strong conada effect.

Putting extra weight into the car will lock its pace until said weight is released.

I am expecting a big upgrade to the rear of the car it's lacking development guessing they wanted to see how far they would of got with such set up.

Improvements to the rear of the car should improve the conada effect and hopefully lowering the fuel needed so it becomes more efficient.

Lewis says he always wanted a rear df car and now he has one and that's good but the rear of the car IMO is their biggest problem

[ringo]

I feel it's duty cycle related. That is with their FRIC suspension. Hamilton didn't sound like he was talking about the tyres. It sounded like he was talking about the car itself.

[cherok1212]

Optimum header length to tune the Coanda effect is where the "black magic" is.

[MercedesAMG]

According to a well-known german newspaper Mercedes has engaged Robert Kubica to upgrade their simulator and for simulator work.

[turbof1]

How do you explain the quali pace? If there troubles are temperature related? So Merc has always been blessed with good condition on saturday? And remarkably every Sunday the condition were bad because the temp was 1 or 2 degrees higher each race? I really don't buy that.

Saturday was the coolest of all the weekend. That and the drivers effectively saying that when the temperatures drop, their car get more performance. (Of course I have to be careful with taking drivers their comments literally; Alonso thought that his rear tyres were gone while it was his drs that was stuck open.)

[dren]

It was Hamilton or Nico who mentioned the set-up coming from the engineers to look after the tires was poor for drive-ability, or something along those lines. Maybe there are a bunch of things not quite adding up here.

What could have suddenly changed, as Hamilton put it, to transform the car? Duty cycle was mentioned of the FRIC system. Could it have been something in the electronics?

[ImAnEngineer]

I think the fact that lewis pitted and fitted hard tyres with less fuel, has more impact then the temp dropping 2 degrees. Hamilton went from option to option and then went to prime. With less fuel and new tyres any car would feel different. The feeling of new rubber and a lighter car explains resurgence more then 2 degrees drop because it was still hot compared to other races. The strategy for lewis worked perfectly. Doing 2 short stints and 1 long one the harder tyres with less fuel is the perfect strategy. Mediums are quicker so you will lose less time and the hard tyres can go longer en is more durable because during stint 3 Lewis had less fuel onboard.

But maybe during the season Ted Kravtiz or some one can ask Ross.

While you have some nice theories a lot of your logic is flawed.

I don't recall where the MS said they run 15kg heavier than other cars, but if true that will be relative to the LIGHTEST cars (Renault), not others running Mercedes engines (which are confirmed as consuming more fuel for higher power). Also 15kg is NOT 1.5s/lap, it is probably closer to half that on a pure weight basis, but then they have additional power which will offset some of that too.

Having an extra 15kg of fuel is NOT going to have an impact on tyre degradation.
Approximate total vertical tyre force =~(640kg car mass+ 150kg fuel)*9.8 + ~15000N of downforce = 22500 N. An extra 150N is negligible.

Also, it is actually very common to fuel save in races. When a team says that they "under fueled" it doesn't mean that they forgot to put in 20kg of fuel at the start. It was calculate before the race that they would run a certain number of laps in a lower mix mode, but due to unforeseen circumstances (they may have been fighting more with other cars than expected) they may have to severely limit their fuel consumption towards the end of the race. These cars are always crossing the line with the bare minimum of fuel left in their tanks (typically less than 1kg above the FIA sample) unless there is an extended safety car period.

The main problem MAMG have is that they overheat the rear tyres (as they have done for the last couple of years).
This could be due to a large number of reasons:
Lack of rear downforce causing the tyre to slide
Heat from exhaust
Suspension geometry / FRIC
Others (that nobody, even highly experienced engineers in a top Formula 1 team, can think of)

This HELPS them in qualifying where getting the tyres up to temperature in the space of 1 lap is necessary to maximise the grip and therefore speed.
In the race, these temperatures will get high and stay high (going above the temperature-grip peak) resulting in slower lap times, or forcing the drivers to slow down to cool the tyres. A lot of the drivers talk about how they only drive at 80% in the race to save the tyres. Maybe the Merc drivers have to drive at 75% to save the tyres. This would be more likely to account for the difference we see in the laptimes.

[beelsebob]

Also, it is actually very common to fuel save in races. When a team says that they "under fueled" it doesn't mean that they forgot to put in 20kg of fuel at the start. It was calculate before the race that they would run a certain number of laps in a lower mix mode, but due to unforeseen circumstances (they may have been fighting more with other cars than expected) they may have to severely limit their fuel consumption towards the end of the race. These cars are always crossing the line with the bare minimum of fuel left in their tanks (typically less than 1kg above the FIA sample) unless there is an extended safety car period.

This actually rather directly contradicts what you just said. The teams consider it faster to take 20kg of fuel out of the car and run deliberately slow for a while than to have 20kg extra in the car. Given that fuel saving can cost you a *lot* of seconds a lap, doesn't that rather contradict your assertion that 15kg of extra fuel will only cost about 0.75s a lap at the start of the race?

The main problem MAMG have is that they overheat the rear tyres (as they have done for the last couple of years).
This could be due to a large number of reasons:
Lack of rear downforce causing the tyre to slide

How about more fuel causing the tyre to slide. It may only be an extra 150N, but that may just be enough to push things over the edge, and cause the tyres to slide just that bit too much.

Heat from exhaust

I can believe that one – Hamilton even aluded to it in his post race interview, but it doesn't explain the poor form at the start of the race, and good form at the end of the race. In fact, tyre wear in general doesn't explain it.

This HELPS them in qualifying where getting the tyres up to temperature in the space of 1 lap is necessary to maximise the grip and therefore speed.

But as we've seen, it's not just qualifying when the car is fast. It's any phase where the car is light on fuel, including mid race.

In the race, these temperatures will get high and stay high (going above the temperature-grip peak) resulting in slower lap times

Which debunks this as an explanation for why the car performs better at the end of the race than at the start.

[turbof1]

It doesn't sound like much, but a 2 degree celcius drop in temperatures could be the difference between 75% and 80%. The harder tyres are harder to overheat anyhow.

If additional fuel was the problem, we wouldn't see such a dramatic improvement all of a sudden. Rather, it would be gradual improvement then.

This actually rather directly contradicts what you just said. The teams consider it faster to take 20kg of fuel out of the car and run deliberately slow for a while than to have 20kg extra in the car. Given that fuel saving can cost you a *lot* of seconds a lap, doesn't that rather contradict your assertion that 15kg of extra fuel will only cost about 0.75s a lap at the start of the race?

It doesn't. He is pointing at predicting circumstances where all cars are forced to drive slower and so burn less fuel. Malaysia started in the wet, and Mercedes predicted that it would stay so for a longer time. That did not happen.

It is the same thing at Monaco: they underfuel there quite alot because chances a safety cars comes out are very high (and with less then 50% of the track on throttle, you can very much afford going into fuel saving mode if the safety car stays inside).

[ImAnEngineer]

This actually rather directly contradicts what you just said. The teams consider it faster to take 20kg of fuel out of the car and run deliberately slow for a while than to have 20kg extra in the car. Given that fuel saving can cost you a *lot* of seconds a lap, doesn't that rather contradict your assertion that 15kg of extra fuel will only cost about 0.75s a lap at the start of the race?

Sorry I should have been more clear - They under fuel specifically for the start of the race where having as light a car as possible is necessary to pull out any advantage. All of the drivers will be using full engine power for the first 10 or so laps (where it is most critical), but later on the advantage of using high power / more fuel is limited.

How about more fuel causing the tyre to slide. It may only be an extra 150N, but that may just be enough to push things over the edge, and cause the tyres to slide just that bit too much.

Can you explain why you think more fuel would cause more sliding?

it doesn't explain the poor form at the start of the race, and good form at the end of the race. In fact, tyre wear in general doesn't explain it.

I never said it was the whole problem!

But as we've seen, it's not just qualifying when the car is fast. It's any phase where the car is light on fuel, including mid race.

Which debunks this as an explanation for why the car performs better at the end of the race than at the start.

There are other factors that come into play towards the end of a race too.
Other cars may be fuel saving more
Track has rubbered in significantly (may benefit Merc's tyres more than others for some reason)
Likely to be running in cleaner air as cars are more spaced out
Later in the day => cooler (even if its only 1-2 deg)

[beelsebob]

This actually rather directly contradicts what you just said. The teams consider it faster to take 20kg of fuel out of the car and run deliberately slow for a while than to have 20kg extra in the car. Given that fuel saving can cost you a *lot* of seconds a lap, doesn't that rather contradict your assertion that 15kg of extra fuel will only cost about 0.75s a lap at the start of the race?

Sorry I should have been more clear - They under fuel specifically for the start of the race where having as light a car as possible is necessary to pull out any advantage. All of the drivers will be using full engine power for the first 10 or so laps (where it is most critical), but later on the advantage of using high power / more fuel is limited.

Right, so the assertion here is that Merc can't gain that advantage of having a lighter car at the start of the race, because they need to carry around the fuel it would save extra anyway.

How about more fuel causing the tyre to slide. It may only be an extra 150N, but that may just be enough to push things over the edge, and cause the tyres to slide just that bit too much.

Can you explain why you think more fuel would cause more sliding?

Because more mass to accelerate (at the same rate), means more force needed to accelerate it, means more force required from the rubber's tensile strength (can't happen), or less acceleration (means either taking the corner slower, or understeering, and in doing so sliding).

it doesn't explain the poor form at the start of the race, and good form at the end of the race. In fact, tyre wear in general doesn't explain it.

I never said it was the whole problem!

Right, but the above explanation about fuel load was proposed as an explanation for why Merc were slow at the start of races, but not at the end. Your explanation (while valid) does not address that, it addresses something entirely different.

But as we've seen, it's not just qualifying when the car is fast. It's any phase where the car is light on fuel, including mid race.

Which debunks this as an explanation for why the car performs better at the end of the race than at the start.

There are other factors that come into play towards the end of a race too.
Other cars may be fuel saving more
Track has rubbered in significantly (may benefit Merc's tyres more than others for some reason)

Okay, but then you're using two completely different explanations to explain the effect of fast qualifying and fast end of race, but slow start of race. Occam's razor seems to suggest that the above explanation that is much more simple is more likely to be the right one, no?

Likely to be running in cleaner air as cars are more spaced out

Except that this wasn't the case at bahrain. Lewis was in fact in clean air at the start, and then overtaking at the end.

Later in the day => cooler (even if its only 1-2 deg)

Possible, but again, I Occam's razor seems to suggest the likely explanation is simpler than needing multiple effects to explain this.

[ImAnEngineer]

Possible, but again, I Occam's razor seems to suggest the likely explanation is simpler than needing multiple effects to explain this.

It is definitely NOT a simple thing involving "one effect", real systems do not work like that. Everything is convoluted and reliant on everything else, if it wasn't F1 teams wouldn't need very clever people working for them

I'm not saying that my explanation is correct, just giving more likely alternatives to what some parts of the problem might be. I'm also trying to make people understand that while creating these "theories" is fun there are so many factors involved that we have no understanding of that more than out weigh any possible correlation they might think they have found in the lap times.