11 replies to this topic

[CountDooku]

It's always been mentioned that the three fuel thirsty tracks in F1 are Barcelona, Bahrain and Montreal. But why? What characteristics of these circuits make them fuel thirsty?

 

Is it because of high top speeds (Bahrain & Montreal)? Monza and Silverstone have high top (and average) speeds but aren't thought of as fuel thirsty.

 

Is it because of fast corners (Barca)? Suzuka and Silverstone have lots of fast corners but aren't thought of as fuel thirsty.

 

Is it because of chicanery, big braking and hard accelerations (Montreal)? Monza and Singapore are also stop-start but aren't thought of as fuel thirsty.

 

From my ancient knowledge of physics, mechanics and road autos, I've always thought that cars consume the most fuel when their engines do the most work. I've thought that this happens under hard acceleration and also at vmax. Given this, I would think that tracks like Monza (stop-start) and Monza (vmax) would be top of the list but they aren't.

 

Can someone please halp?!

[Clatter]

It's because they spend more time on full throttle at those circuits.

[FerrariV12]

I'm not an expert but from what I vaguely know, there are a few factors.

 

Acceleration and particularly deceleration. Maybe less so in the ERS era, but certainly before it, circuits with lots of heavy braking you were literally wasting energy (fuel). With the energy limits and only generating from 2 wheels, that will still be a factor today even if less so. Monza, well see below, and Singapore I don't think they reach the top speeds they do in say Montreal or the old Imola, so while it's a slow circuit, lots of braking, there's less heavy braking moments.

 

Also drag plays a part as well - tracks like Monza they tend to run low drag setups, so you need less energy to cut through the air than you would at other tracks.

 

Also gearing has to be taken into account. A car doing vmax (say 200mph for ease of example) may be burning more fuel than one doing 50mph, but not 4 times as much, particularly if that 50mph car is accelerating out of a turn in a low gear at the time, so that equals more mpg and less fuel used over the race distance.

Edited by FerrariV12, 10 June 2015 - 09:58.

[CountDooku]

It's because they spend more time on full throttle at those circuits.

 

If you are talking about time on full throttle, then surely the circuits with the highest average speeds should be top of the lost? If I recall correctly, the list is something like this for avg speeds.

 

1. Silverstone
2. Monza
3. Spa
4. Montreal

[CountDooku]

To extend a bit on what Clatter said, and to bring Monza into this, you have to keep in mind, that for fuel consumption (apart from other aspects like drag/downforce levels etc.), you have to consider the "absolute" time ( in sec) which is spend on WOT during a race.

Monza may has the highest % of WOT during a lap, but because of the high average speed, and the fact that the races are set by distance, you have two effects at play here.

The absolute time per lap at WOT isn't all that long (because the laptime is low), and the race is over "quick" w.r.t race duration ( time ).

 

To illustrate what I mean, let's consider two examples to illustrate the point:

 

race 1.)  75% of wot , average laptime   85s = 0.75*  85 = 63,75s * 53 laps = 3379s per race

race 2.)  60% of wot , average laptime 102s = 0.60*102 = 61,20s * 56 laps = 3427s per race

 

In this case, race 2, would (if we consider other things the same, and concentrate on consumption due to time at wot), have the higher fuel consumption over a race distance.

 

Understood, but going back to the V8 era where there was no limit on fuel carried during the race, you would expect teams to carry enough fuel in race 2 to not make it an issue, yet Barcelona has always seen some fuel saving (teams under-fuel everywhere so you wouldn't expect them to under-fuel more in Barca than elsewhere).

 

Or perhaps the issue today with the 100kgs limit is that teams are actually getting pretty close to this limit on the "fuel thirsty" tracks?

 

Would you happen to have data of the GP distances travelled per track?

[BillBald]

 

If you are talking about time on full throttle, then surely the circuits with the highest average speeds should be top of the lost? If I recall correctly, the list is something like this for avg speeds.

 

1. Silverstone
2. Monza
3. Spa
4. Montreal

 

 

When calculating time on full throttle, you need to take account of the total race time. Monza race is typically over in 1 hr 15 mins, other races can last nearly 2 hours.

 

Edit: I see that TC3000 covered this in more detail.

Edited by BillBald, 10 June 2015 - 11:01.

[RainyAfterlifeDaylight]

Circuits with short straights and more corners don't need top speed because the cars can't reach it's top speed in those kind of circuits even if the power unit is fully turned up, So the cars can do a fast lap without reaching their top speed so power unit is in cruising mode (Less fuel usage)

 

Circuits with long straights need high speed and the cars can reach the maximum speed on the straights to do their fast lap (More fuel usage)

Edited by RYARLE, 10 June 2015 - 11:18.

[Kalmake]

 

If you are talking about time on full throttle, then surely the circuits with the highest average speeds should be top of the lost? If I recall correctly, the list is something like this for avg speeds.

Not really. Consumption doesn't go up linearly with speed. Slower the corners and longer the straights, the more time is spent on full throttle. For example Copse to Chapel versus Montreal hairpin to last chicane.

[Goron3]

Long and hard acceleration zones, hence why Australia, Canada, Bahrain and Singapore are heavy on fuel compared to Suzuka, Silverstone and Monza.

[Marklar]

Stop and go circuits are the most fuel thirsty. Hard braking and then again fully on the gas. This non-stop closing and full opening of the throttle leads to the high fuel demand on Circuits like Melbourne, Spa, Bahrain, Singapore or Montreal.

Edited by Marklar, 10 June 2015 - 11:30.

[GrumpyYoungMan]

Understood, but going back to the V8 era where there was no limit on fuel carried during the race, you would expect teams to carry enough fuel in race 2 to not make it an issue, yet Barcelona has always seen some fuel saving (teams under-fuel everywhere so you wouldn't expect them to under-fuel more in Barca than elsewhere).

 

Or perhaps the issue today with the 100kgs limit is that teams are actually getting pretty close to this limit on the "fuel thirsty" tracks?

 

Would you happen to have data of the GP distances travelled per track?

Its also the safety car calculation they add into the calculation... as if there is a high chance of the race normally having a safety car they will fuel according to that risk.

 

At the end of day every bit of weight you carry is a disadvantage over a race/lap distance...

 

That's why if they (were to) simply allowing refueling during the race the cars will be faster due to the weight loss...

[Bob Riebe]

 

Is it because of , big braking and hard accelerations

Yes.