Bathurst Fuel Consumption

[00 XR8]

The Sandown circuit is exactly half the length of Bathurst, so I took the lap number of people’s first stop at Sandown and divided it by 2. This should give an approximate of how many laps each car will be able to do at Bathurst on one take of Optimax. I realise that there are a few variables (such as large number of Safety Cars at Sandown and the fact that going up a mountain should use more juice) but pre-Bathurst calculations are always fun……..

#9 Caltex – 23
#1 Pirtek – 24
#10 Orrcon – 27
#17 Shell – 28
#6 Caterpillar – 29
#29 Sirromet - 29
#51 K-Mart – 29
#12 OzEmail – 30
#34 Valvoline - 30
#50 PWR – 31
#31 SuperCheap - 32
#2 HRT – 32

This looks catastrophic as far as SBRs fuel consumption goes, but both SBR Falcons did 56 laps from their final stops to the flag (28 laps in Bathurst language) at Sandown. So where they not full on the grid, or was pitting earlier part of their strategy, because they definitely pitted before they had too?

Anyway, to get away with four stops, you need 40 laps out of a tank so that seems quite out of reach for everyone. Five stops is 32 or 33 laps per tank, so #12, #34, #50, #31 and #2 are within striking distance of that mark, but it will be a real stretch. I am not convinced that K-Mart or the SBR cars pitted at Sandown with a low fuel light on, so I think they can go a little further at Bathurst.

Even if one car can do it with no spash-‘n-go, I don’t think it will make much difference, because if everyone else pits on lap 15 or there abouts, then it will just put you at the front with the other 34 cars filed up right on your tail the next time a Safety Car comes out.

I think everybody then will use 5 stops and a splash and dash. So using the SBR strategy from 1998 (and what most did last year) expect stops at around……..

Lap 15 (a top up or full tank, depending on what you started with)
Lap 45
Lap 75
Lap 105
Lap 135 which will take them all the way to the flag.

We have more HP every year, and worse fuel consumption. But really, everyone will need to make 5 and a splash, so it doesn’t matter where you are with consumption. If everyone is between 27 and 32 laps on fuel, then everyone will need to be visiting the pits 6 times on October 10…………..

Contrary to the beliefs of some, fuel consumption should not decide who wins this 1000km thriller

[FalconEL]

I always thought it was 4 stops at a stretch and a splash if you needed it.

If you get to lap 33, 66, 99, 132, that's four stops and you're home!!

I remember the Winfield car running about 38 laps in 1995 before it's first stop, so going on past years (and I'll have to drag out the videos), most cars should make 30 laps of Bathurst on a 120 Litre tank. I know they have more HP now, but 30 laps shouldn't be a drama.

Longhurst pitted about 400 times in the Havoline AU one year but was still in the lead with about 15 laps to go before he took himself out......

In an ideal world, a race without safety cars would be bloody fantastic. A true test of economy, not contrived sprints between Safety Cars. Less Safety Cars would make it a much more realistic contest.

[mmciau]

00 XR8,
Thanks for that guestimate. I suspect that the pace and gapping of MA's car at Bathurst will be similar to the pace and gapping he was able to get at Sandown. While watching him at pace, I was wondering what his fuel consumption was but because of the day, we plebs never know. I suppose the only yardstick we might have is Murphy from 2003 but with a different engine - goodness knows what the consumption rates will be.

It will be fascinating seeing the fuel management strategies.
One unnecessary race-pace stop could be a killer.
Mike

[naughtymutt]

The calcuation doesnt take into account the differences in the circuits... longer straights and bigger hills at bathurst. and also the teams could make changes to the engine setup to get extra mileage

[00 XR8]

Originally posted by FalconEL
I always thought it was 4 stops at a stretch and a splash if you needed it.

If you get to lap 33, 66, 99, 132, that's four stops and you're home!!

You are right. I was counting in stints when I said 5 rather than in stops

Sorry bout dat

[FalconEL]

Originally posted by 00 XR8

Even if one car can do it with no spash-‘n-go, I don’t think it will make much difference, because if everyone else pits on lap 15 or there abouts, then it will just put you at the front with the other 34 cars filed up right on your tail the next time a Safety Car comes out.

You're spot on though 00XR8, fuel economy probably won't be an issue. The teams shouldn't have to stretch it to a four stop race although this year, we will have less cars out there and possibly the potential for less carnage and therefore less Safety Cars.

[Onlooker]

There are so many yellows now that the consumption and laps required is an ever changing equation. Most teams I would think would aim to do the least amount that they can, but a yellow that appears, just shy of the fuel window , is too juicey a carrot for a few teams to leave and in they will come, sometimes in hindsight seen as a mastersrtoke by an shrewd engineer, but other times a poorly calculated error that is chuckled about by others
The arrival of patchy rain, pretty much removes any fuel consumption problems as the tyres are now dictating when the car stops not the fuel.
SBR pulled off the big suprise with Bright and Richo slipping in on around L15, the next year, they did it, along with plenty of others and there were pit booms being towed up pit lane and a whole host of drama's. it is a bit of a raffle i think. but by lap 155 the scene is usually pretty much set, and all the cards are on the table,up untill then, you never know who has a "spash and go" looming up on them.

[Lowndesfan6]

Correct me if I'm wrong but don't they use a longer diff ratio as well at Bathurst, this will effect milelage.

[Onlooker]

But the same every year, so the equation at Bathurst remains the same

[amaroo]

Interesting to note at Sandown the SBR engines " seemed " to use fuel quicker than their competitors. For Ambrose and his pace this was no problem (if it was using more?) as his overall pace was quick to make up any additional fuel consumption. What about Bargs and Co. if they also (as it appeared)use a little more gas than others but dont have the chassis package to go head to head with Pirtek pace could this prove to be costly - For example Ambrose fastest lap at Sandown 1.10.82 , Bargs 1.11.70 .... multiply that over 1000k's and....... well as OO XR8 said pre Bathurst calcs are always fun

[tiko]

Its all about how long your on full throttle and the carsare increasingly on full throttle now more so than ever, especially if you have really good drive off the corners, as does ambrose, you will be on full throttle longer, therefore using more fuel, therefore requiring to pit earlier for fuel, but if there are as many safety cars at bathrust as there was at sandown, cars will easily do 4 stops, however some teams are pushing for compulsory 5 stops at bathurst.

[onfullnoise]

just because you are on full throttle longer, this does not mean you will use more fuel...

[rdmdog]

Plenty of safety cars may have increased the ammount of time that some cars were on the track too.

You could really see the smoke from the cars as they drove under the bridge on the weekend.

[dynamik gal]

A full lap under green conditions at Sandown consumed roughly 2 litres of fuel. So if Bathurst is twice the length, and bearing in mind the extra grunt it needs to get up the hill, i'd calculate fuel consumption to be just on 4.5 litres per lap, perhaps even more.

If we round up to 5 litres per lap in a tank that holds 120 litres, thats 24 laps it can go under green conditions at Bathurst - being conservative.

Bearing in mind at last year's Bathurst:

* Majority of cars pitted on Lap 33/34

* Murphy/R.Kelly pitted 4 times throughout the race and won.

* Before lap 33 there were 2 safety car periods totaling 5 laps, therefore laps under green were approx 28.

* Multiply 28 laps by 4.3 litres of fuel = 120 litres = start with full tank.

[Conrod Kieron]

Originally posted by Lowndesfan6
Correct me if I'm wrong but don't they use a longer diff ratio as well at Bathurst, this will effect milelage.

Yep. Bathurst used a 3.25 and Sandown 3.5 which means engine revs will be lower at a given speed and of course slightly more economical.

[Mattracer]

There's the self-perpetuating problem of a yellow and then another one almost immediately after it as someone has an off on cooled off/under pressured tyres, so there are plenty of laps under yellow at Bathurst.

Good topic though- this sort of intriguing stuff is where the true speed at Bathurst often lies, and who has enough brakes and enough fuel but not too much for the last 20-30 laps.

[TSR]

Russell Ingall did come out in public ( I think it was on v8supernerds ) and said that fuel will be a drama at Bathurst and perhaps it will be a 5 stop race.

[paydirt]

Did anyone else notice the amounts of thick black smoke coming from the lead SBR Rocket in the early laps ?

Maybe they are comprimising fuel consumption for raw horsepower in the enduro's , knowing that these races have now become a 'safety car fest' and they can recoup the lost time that way...

[Mattracer]

Maybe... did anyone notice #9 issuing the same rich mixture smoke as well?

[Average Punter]

With all the safety cars at Bathurst now, early speed doesn't seem so important any more.

Infact the last 2 times I can remember a car that was markedly faster than the field was in the '97 Super Tourer race with Plato and Menu in that flying yellow Renault, and the Rat's DJR Ford in '99.

Both times they sprinted away from the pack only to be dragged back by the pacecar time and time again. Both times the cars broke too...

Do you think Marcos will play the hare at Bathurst?
Or will he "buy a ticket to the end game..."?

edited by wife. "That was '99 you idiot!!!"

[Grimace]

Originally posted by TSR
Russell Ingall did come out in public ( I think it was on v8supernerds ) and said that fuel will be a drama at Bathurst and perhaps it will be a 5 stop race.

More POWER from SBR = more optimax usage -simple!!!

[paydirt]

Ambrose's performance on Sunday reminded me of the old 'Brock-Crush' days when PB would get out in front and go like hell , while all the other contenders, who started with a more conservative strategy, would see him disappear into the distance. Then they'd all panic & try & play catch up, generally with dire consequences.

For my money, I'd go like hell....

[peckstar]

i dont think we got to see the SBR fuel economy,

they were running to a plan, that saw their first pit at the opening of the brake change window and stopped 104 laps latter(exactly the minimum amount of laps each driver must do ) for the 2nd stop

this gave the no. 1 driver the maximum amout of time in the car for the last stint.

it was a great bit of strategy, which ended with both cars on the podium

[GTRMagic]

With the expected safety cars, I dont think its an issue if the cars have 5 stops anyway.... Dynamik topped both their cars up last weekend at the first safety car.. they were alone in doing so, but it did put both cars out of sequence (on purpose) and gave them some places in traffic they may not have otherwise had.

[peckstar]

GTR
wouldnt that depend on when the 5th stop is made.

Skaife made a fifth stop last year and he went from 2nd to i think it was last(10th or something)

whereas bright made his fifth(ok additional ) stop early in 98 and took the win