Downforce and fuel consumption

  • Thread starter Joker-GTBR
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Joker-GTBR

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GTBR_Joker
Let's think about two race cars in GT5, racing in an average-speed track (example: Autumn Ring). One is with a downforce setup of 10/20. The other is with a downforce of 20/40. Considering the fact their power, weight and drivetrain is the same, and they're running lap times with small difference between them, never catching slipstream, would the car with more aerodynamics have the necessity of pitting more?


In few words: more downforce in GT5 means (totally or partially) greater fuel consumption?
 
more downforce means more fuel consumption, of course because there is more air friction, but i'm not sure GT5 applies this.
 
You might even be using less fuel with more downforce. Consider you have to slow down to 50mph with little downforce, but with more downforce you only need to slow down 65mph. Having more air friction won't necessarily consume more fuel but will slow you down on the straights slightly.
 
This is easily tested with the FGT or X2010 at the Indy 500. The more downforce, the slower...the fewer times you have to pit.
Which isn't 100% realistic.
 
themartlab
more downforce means more fuel consumption, of course because there is more air friction, but i'm not sure GT5 applies this.
Click to expand...

Air friction is one factor, however there if there is more downforce on a car, this squashes the tyres into the track more, thus a greater surface are meaning even more friction with the tarmac. This increases tyre temperature anbd pressure, expanding the rubber even more. 💡
 
leeson
No?
Click to expand...

Why don't you do the experience yourself, for example going with a race car in Bspec mode (on a short track not the ring)

-full downforce /check the first pit stop how many laps and liters to fill the tank.

-minimum downforce /check first pit stop how many laps and liters to fill the tank.

For the Fuel consumption = liters / laps

For the tires = numbers of laps before pit stop.


I think it's possible to know this way.
 
In few words: more downforce in GT5 means (totally or partially) greater fuel consumption?

Yes !! fuel and tires.


CONSOTEST.jpg
 
^^^ wow, thats not just a little unoticeable thing that is a vastly higher consumption on full downforce. Very interesting, thanks for that Praiano.
 
Are you sure that data is correct?
You're telling me that with 10 less liters of fuel, the car went 26 more laps?
Seems more likely that the Min Down force actually pit at 28, then again at 56
Thus only a 2 lap difference between the 2, with Max Aero winning the tire wear question, but losing the fuel consumption aspect.
 
With the higher downforce, your car has more drag on it, meaning that it will require more power to the wheels to go the same speed as the same car with less downforce going next to it. But, higher downforce may decrease the tire wear because... Well there is more downforce on the wheels! If wondering on where to set it, I'd say that it would depend on the track, your tune, and how you drive your car.
 
Adrenaline
Are you sure that data is correct?
You're telling me that with 10 less liters of fuel, the car went 26 more laps?
Seems more likely that the Min Down force actually pit at 28, then again at 56
Thus only a 2 lap difference between the 2, with Max Aero winning the tire wear question, but losing the fuel consumption aspect.
Click to expand...

Actually, from the data, with Max downforce, the tire wear increase about 3.33% per lap, which, after the 30 laps, you have to pit in, change tires. With Min downforce, the tire wear is only 1.79% per lap, which lasted about 55-56 laps, before you have to pit in.

Same as the fuel consumption, running with min downforce, you can have more running laps, before going out of fuel. Hence, MAX DONWFORCE is bad for tire and fuel. Only applied to endurance though.. :sly:
 
SAPPH
More downforce, more tire patch contact, increase tire grip, but increase tire wear..
Click to expand...

Midnight has a good point actually

More downforce = more traction, thus you are spinning out less. And I think he is right, I believe there would be a happy medium somewhere in there, adding downforce at some point would decrease tire wear via less wheel spin, however adding more downforce from this point would certainly increase handling, but decrease tire wear obviously.

this is just speculation, by the way
 
Hmmm... I guess. But, hence


lvl1dnIghT7un3R
With the higher downforce, your car has more drag on it, meaning that it will require more power to the wheels to go the same speed as the same car with less downforce going next to it. But, higher downforce may decrease the tire wear because... Well there is more downforce on the wheels! If wondering on where to set it, I'd say that it would depend on the track, your tune, and how you drive your car.
Click to expand...

Maybe somewhere in the middle would be the sweet spot.
 
Based on my extensive practice, testing and racing NASCAR, More downforce results in LESS tire wear. B Spec drivers fail.
 
From what i heard, when increasing downforce, we can achieve higher cornering speed, thus heavy stress on the tires causes tire wear.

On long straight stretch, the tire wear probably can be neglected.

But, on lower downforce, if you try to increase the pace during corners as you would on higher downforce, you also create higher stress on the tire, still causes the tire to wear faster due to sliding.

I think Midnight also have got the point. Depends on the track, your tune, and how you drive your car.

The point in reducing the tire wear is optimum balance.

P/s: I'm no expert, still learning though. Pardon if i make mistakes.
 
Adrenaline
Are you sure that data is correct?
You're telling me that with 10 less liters of fuel, the car went 26 more laps?
Seems more likely that the Min Down force actually pit at 28, then again at 56
Thus only a 2 lap difference between the 2, with Max Aero winning the tire wear question, but losing the fuel consumption aspect.
Click to expand...

Sorry, you're right, when i did the second part with mini downforce , i was busy and i couldn't stay in front of the game .
When i came back to check , it was the second pit it seems.
So i did it again and it give a little more tire waste with mini downforce, just a few, the car stoped fo,r the pit at lap 29 in the way of 31, but the fuel consumption was proportionally lower.

Need to repeat on other tracks with other kind of race cars.

consotest2.jpg
 
^Praiano, did you keep the gearbox, or did you tweaked for more speed?

Adrenaline
Based on my extensive practice, testing and racing NASCAR, More downforce results in LESS tire wear. B Spec drivers fail.
Click to expand...
THIS 👍

I usualy run 1:30h races on Lmp cars with a butch of friends of mine and tire wear is a real issue, what i've found out is that, the more stable the car is the less tire wear it will have, that's why we all use full aero regardless the track. And everybody knows when you're running nascars, if you wanna do a few more laps on the same tires, you use rear aero... just like adrenaline said.

More aero = More Grip = Less Skid = Less Tire Wear

In the fuel consumption department, I believe that gear box has more to do with it than aero... Bare with me, if you use less aero in a car you will have more max speed, if you keep the same gearbox you will get higher rpm thus more fuel consumption but if you use a longer gearbox you probably will get the same fuel consumption.

Will do a test on this tomorrow....
 
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Goruk
^Praiano, did you keep the gearbox, or did you tweaked for more speed?


THIS 👍

I usualy run 1:30h races on Lmp cars with a butch of friends of mine and tire wear is a real issue, what i've found out is that, the more stable the car is the less tire wear it will have, that's why we all use full aero regardless the track. And everybody knows when you're running nascars, if you wanna do a few more laps on the same tires, you use rear aero... just like adrenaline said.

More aero = More Grip = Less Skid = Less Tire Wear

In the fuel consumption department, I believe that gear box has more to do with it than aero... Bare with me, if you use less aero in a car you will have more max speed, if you keep the same gearbox you will get higher rpm thus more fuel consumption but if you use a longer gearbox you probably will get the same fuel consumption.

Will do a test on this tomorrow....
Click to expand...

All the rest was stock settings, but the gearbox with a classic tranny trick. Close gears.
 
praiano63
Sorry, you're right, when i did the second part with mini downforce , i was busy and i couldn't stay in front of the game .
When i came back to check , it was the second pit it seems.
So i did it again and it give a little more tire waste with mini downforce, just a few, the car stoped fo,r the pit at lap 29 in the way of 31, but the fuel consumption was proportionally lower.

Need to repeat on other tracks with other kind of race cars.

consotest2.jpg
Click to expand...

Much better.

@Goruk, you're on the right track, but even with RPM's consistent, among high/low downforce, the less downforce should use less gas, simply due to less resistance.
 
So did PD actually program something correctly here? Seems that there should be a reward for making cars work with more mechanical grip/less downforce.
 
I think problem solved. Higher downforce = less tyre wear but higher rate of fuel consumption.

@MotorCityHami
I think so...

SAPPH
From what i heard, when increasing downforce, we can achieve higher cornering speed, thus heavy stress on the tires causes tire wear.
.........
Click to expand...

The reason we can achieve faster cornering speed is because of the higher grip. 👍
 
lvl1dnIghT7un3R
I think problem solved. Higher downforce = less tyre wear but higher rate of fuel consumption.

@MotorCityHami
I think so...



The reason we can achieve faster cornering speed is because of the higher grip. 👍
Click to expand...

The thing is that because the tire wear is slower and the fuel consumption is faster, well... your car accelerates better with less fuel load, correct? These pit stops are tire limited it seems. Since they BOTH have to refill to full (and 10 extra liters is not that much considering the faster lap times due to the higher cornering speed) the car with higher downforce will eventually be getting better acceleration due to the lower fuel load.

Though obviously if pit stops are tire limited, you're probably going to be filling the fuel tank up to about 2 liters over what you'll need until the next pit stop.

Basically what I can draw from this is: Always go at max downforce, ESPECIALLY in online rooms where fuel consumption and tire wear are off.

Edit: Yes, I know this can be considered a necro. My apologies, but I feel this is sort of relevant to the topic anyway.

My tests of a 370Z Tuned car at Downforce 5/5 versus Downforce 15/20 (keeping both cars at the same PP) yielded the higher downforce car with less power winning by 1.1 seconds on Deep Forest.
No settings other than HP and Downforce were modified. Both cars were run on SS tires.

A 7% sacrifice in horsepower is more than made up for my its longer power band and higher cornering speed while more stable nature on a track where momentum and power are both critical. It also is able to swing its tail around a bit at low speed to get the car pointed nicely, or being smooth will cause it to stick firmly to the road. It has the advantages of a low downforce car at lower speed and the advantages of higher mid to high corner speed.

In addition, over the course of 20-30 laps, this 1 second disparity more than makes up for the increased fuel consumption because of the lower tire wear as well. Over an endurance of about 50 laps on Deep Forest, I'd hedge my bets on the high downforce car nearly lapping the low downforce car.
 
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Downforce, tyre/fuel wear is dependent on the car and regulations being used.

Take a FWD car, low power high grip tyres - you want low rear (compared to front) as this helps the back rotate in faster corners, saving front tyres.

Take same car, max the power and reduce tyres to comforts, sports hards, you probably want higher downforce to hold the car steady and give it balance to stop it moving around and wearing the tyres, or increasing the chance of a mistake (spin) which help burn tyres out even quicker.

Same principle on different drivetrains - you need to establish whether you need downforce to help stabilise the car or loosen it - each car/regulations and track is going to different. You can also add driving styles and setup to the variables too. You also have to consider whether saving pp points through aero and using them for power/weight use might be better.

Fuel isn't so much of a worry, we race endurance races with high tyre/fuel wear - getting the amount of fuel correct at pit stops is more important than anything trying to make consumption better.

No point trying to save a few seconds in the pits if you make the car difficult to drive when tyres are cold or worn and you end up spinning, crashing or generally loosing excess time through things going wrong/badly.

Sometimes detuning a car so its slower at the start, but you end up saving time when the tyres are less than 50%/33% and you still have laps to do before pitting.

In most situtations tuning for fuel is irrelevant, tuning for a good balanced setup and tyre wear will far outweigh it in both importance and results i.e. race/tyre stint times.

Most tyre/fuel settings will have the tyres burning out long before fuel gets close to running out or being an issue, probably a few exceptions but this is 99% what happens with all cars in all situations.

Concentrate and getting the car balanced throughout tyre life in race - helps reduce mistakes and subsequent lost time.

Again, this is subjective to rules/regulations (and alot else) - doing a 3 lap/5 minute race with low wear and fuel won't make any of this relevant, you might aswell max the setup.

But when you're doing 1 or 2hr real time races, things are alot different - especially with higher wear on.
 
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