Quick Clarification About Power/Torque Figures and Units

This is a [no longer] small guide to help understanding which power and torque figures are correct, according to the units for Power and for Torque selected in the 'Options' menu.

Units available for Power: PS, HP, BHP, CH, kW, CV, PF

Units available for Torque: kgf.m, ft.lb, NM

Power

There are at least 6 places (that I know of) where the Power of a vehicle can be checked:

1) Garage Screen (where up to 10 vehicles of the ones currently possessed are listed)
2) Car Screen (screen that appears after clicking on one particular vehicle)
3) Sell Screen (screen that appears after clicking on the Sell icon)
4) Settings Screen (screen that appears after clicking on the Settings icon, before a race) - (Power is shown in the small Power and Torque Graph, top right of the screen)
5) Settings Screen (screen that appears after clicking on the Settings icon, before a race) - (Power is shown in the big Power and Torque Graph, which can be brought up by pressing Start)
6) Replay (at the beginning of it, Power is listed along with choice of tires, among other things)

Example (note I set HP as my units for Power):

MINOLTA Toyota 88C-V Race Car '89, Stage 4 Turbo:

1) 1223HP
2) 1206HP
3) 1206HP
4) 1223HP
5) 1206HP
6) 1148HP

I was discussing this with Small_Fryz and he suggested for me to check if maybe the digits shown in the Garage Screen and in the small Power and Torque Graph (see 1) and 4)) are shown in the amount they would be in PS, regardless of the units chosen in the Options. So I changed the units to PS, and sure enough, the value of 1) and 4) did not change. Thanks to Small_Fryz for pointing this out.

This is the outcome of choosing PS for the units of Power:

1) 1223PS
2) 1223PS
3) 1223PS
4) 1223PS
5) 1223PS
6) 1164PS

So, as we can see, all the figures now match (except for the one in the Replay), and are all in the same units. Therefore Small_Fryz was correct, the digits shown in the garage screen always refer to PS, regardless of the choice of units made in the Options. Same for the digits shown in the small Graph, within the Settings screen.

Therefore, the only places where YOUR choice of units (provided that your choice is different than PS) for Power is reflected are these:

1) Car Screen (screen that appears after clicking on one particular vehicle)
2) Sell Screen (screen that appears after clicking on the Sell icon)
3) Settings Screen (screen that appears after clicking on the Settings icon, before a race) - (Power is shown in the big Power and Torque Graph, which can be brought up by pressing Start)
4) Replay (at the beginning of it, Power is listed along with choice of tires, among other things)

Everything else is always in PS, and the digits will not change, even if other types of units are selected for Power, in the Options (oddly enough, though, the different units will be appended to the number, even if the number is always the same - the one it would be if PS was chosen).

Changing the units to BHP, CH (1CH = 1PS), kW, CV (1CV = 1PS), PF (1PF = 1PS) does not induce any change into the number shown in the Garage Screen or in the small Power and Torque Graph. Everything else changes accordingly, though.

Moving onto...

Torque

There are at least 3 places (that I know of) where the Torque of a vehicle can be checked:

1) Car Screen (screen that appears after clicking on one particular vehicle)
2) Sell Screen (screen that appears after clicking on the Sell icon)
3) Settings Screen (screen that appears after clicking on the Settings icon, before a race) - (Torque is shown in the big Power and Torque Graph, which can be brought up by pressing Start)

Example (note I set kgf.m as my units for Torque):

MINOLTA Toyota 88C-V Race Car '89, Stage 4 Turbo:

1) 112.95 kgf.m
2) 112.95 kgf.m
3) 113 kgf.m (note this one is rounded up to show an integer number - no decimal places)

This is the outcome of choosing ft.lb for the units of Torque:

1) 816.96 ft.lb
2) 816.96 ft.lb
3) 817 ft.lb (note this one is rounded up to show an integer number - no decimal places)

And, lastly, this is the outcome of choosing NM for the units of Torque:

1) 1106.91 NM
2) 1106.91 NM
3) 1107 NM (note this one is rounded up to show an integer number - no decimal places)

As it can be noted, all the digits are reflected correctly (so were the ones for Power, in those particular locations).

Therefore, it is to be concluded that the digits in the Garage Screen and in the small Power and Torque Graph (visible within the Settings Screen) do not mirror the user's choice for the Power units, while the digits shown in the Car Screen, Sell Screen and the big Power and Torque Graph (visible within the Setting Screen, after pressing Start) match correctly the unit selection made into Options (for both Power and Torque).

Here are some useful conversion factors:

1 HP = 0.745 kW

1 kgf.m = 7.23 ft.lb
1 kgf.m = 9.81 NM
1 ft.lb = 1.36 NM

UPDATE - The following information was added April 10, 2005

I have just spent the past couple of days doing some more testings to figure out why the power figure shown on the Replay screen does not agree with the other "accepted" figures (Car Screen, Sell Screen, and big Power and Torque Graph).

I started with the assumption, originally suggested by blurred (see post #3, below), that the power shown on the Replay screen would be the power the vehicle would have without performing an oil change (when bought anew).

Therefore, I bought a new Dodge SRT4 '03 and tested it*.

1) 0 miles, without oil change:
- Shown on Car Screen: 230HP
- Shown on Replay Screen: 229HP

I immediately thought: "Not good. If I perform an oil change, the car will end up having even more horsepower. 229HP must refer to something else."

I did test it with an oil change, nonetheless:

2) 0 miles, with oil change:
- Shown on Car Screen: 241HP
- Shown on Replay Screen: 229HP

Well, good. At least the power figure on the Replay screen stays constant (for a given vehicle configuration).

Would the power shown on the Replay screen be the power the vehicle would have with "really" dirty oil? (it is known, from GT3, that the modifier for dirty oil for a vehicle bought at a dealer is lower [in magnitude] than the modifier for dirty oil coming from high mileage).

Well, only one way to check. I went to the Used Car Showroom II and picked me up a Honda S2000 Type V '01, with 24,266.4 miles.

Here are the results from testing the Honda S2000 Type V '01:

1) 24,266.4 miles, dirty oil (oil light was on):
- Shown on Car Screen: 220HP
- Shown on Replay Screen: 243HP

Ok, we are good. An oil change should hopefully bump it back up.
And, sure enough...

2) 24,266.4 miles, clean oil:
- Shown on Car Screen: 243HP
- Shown on Replay Screen: 243HP

Ok, then the oil light needs to be on, in order for the car to achieve its minimum power? Not likely. The car had 24,266.4 miles. That includes permanent power drop for the engine (same way it happens in GT3).

Only one other way to test this: take a new (0 miles) MINOLTA Toyota 88C-V Race Car '89, slap a Stage 4 Turbo, take it to the Test Course (in the "Driving Park" section), and let the B-spec driver drive the hell out of it. How long could it take? In GT3 the permanent power drop happened within the first few hundred miles anyway. I couldn't have been further from the truth

It took 650 miles just for the permanent power drop process to start. I kept driving it in B-spec for about 300 miles at a time, quitting, changing the oil, checking the power value and the mileage, and plotting the results with Excel. It seemed a pretty linear relationship, so I fitted a line and found analytically how many miles it would take for the power to drop to 1148HP (the value listed on the Replay screen, for the MINOLTA Toyota 88C-V Race Car '89 fitted with a Stage 4 Turbo). The value turned out to be ~8100 miles. I let B-spec run it up to that point, and then checked the amount of horses that were still alive. 1150. Close, but not close enough. I still run it in B-spec, checking every 50 miles or so. The vehicle finally got to 1149 at ~8400 miles. I took over, and run 25 mile legs at a time. Finally, the car reached 1148 at 8495 miles. The value shown on the small Power and Torque Graph was 1165PS, though. I thought, sure the mileage value has to be a "whole" number. So, I run the car one mile at a time, and finally, at 8500 miles the value shown on the small Power and Torque Graph dropped to 1164PS. That's the minimum value of power this vehicle will reach, with a Stage 4 turbo, due only to engine wear [all the numbers were checked with clean oil].

I let the vehicle run in B-spec for another couple hundred miles, just to make sure the power would not drop any further (due to engine wear), and sure enough, 1164PS - 1148HP was the lowest value.

Therefore, the theory is proven.

The power value shown on the Replay screen is the amount of power the vehicle would have once the engine has experienced the maximum power drop due to mileage (which happens to occur at 8500 miles, while the power drop process itself starts at 650 miles), with clean oil.

Summary:

MINOLTA Toyota 88C-V Race Car '89, Stage 4 Turbo:

1) 0 miles, with oil change
- Shown on Car screen: 1206HP
- Shown on Replay screen: 1148HP

2) 8500 miles, with oil change
- Shown on Car screen: 1148HP
- Shown on Replay screen: 1148HP

I also did two more tests, to see if this would apply to a stock MINOLTA Toyota 88C-V Race Car '89.

MINOLTA Toyota 88C-V Race Car '89, stock:

1) 0 miles, with oil change
- Shown on Car screen: 952HP
- Shown on Replay Screen: 906HP

2) 8500 miles, with oil change
- Shown on Car screen: 906HP
- Shown on Replay screen: 906HP

As it can be seen, the last value of test 1) matches the two values of test 2), for both the vehicle fitted with Stage 4 Turbo and the vehicle stock, respectively.

Summary:

1) Vehicle tested starts experiencing permanet power drop at 650 miles
2) Vehicle tested reaches maximum permanent power drop (and therefore minimum power available with clean oil, for a given configuration) at 8500 miles
3) Power shown on the Replay screen is amount of power the vehicle would have once reached its maximum power drop due to mileage, with clean oil
4) Both the Dodge SRT4 '03 and the MINOLTA Toyota 88C-V Race Car '89 experience a ~5% permanent power drop from their 0 miles condition to the condition stated in the Replay screen (which, at this point, is assumed to be the one stated in 3))
5) It appears no "break in" period is present in GT4 (it was, in GT3), as the Dodge SRT4 '03 did not gain any additional amounts of power, even if run extensively on the Test Course. Therefore, it can be concluded that in GT4 neither prize vehicles nor purchased vehicles need to be "broken in", in order to be at their highest amount of power

I am aware more vehicles need to be tested, in order to confirm the mileage, and the percentage of power drop, but it can be safe to say that the value shown on the Replay screen is indeed the minimum power the vehicle will reach with clean oil.

*All the tests were performed in "World Circuits", Infineon Raceway - Sports Car Course, unless otherwise stated.

The Wizard.

TheWizard

Therefore, the only places where YOUR choice of units (provided that your choice is different than PS) for Power is reflected are these:

1) Car Screen (screen that appears after clicking on one particular vehicle)
2) Sell Screen (screen that appears after clicking on the Sell icon)
3) Settings Screen (screen that appears after clicking on the Settings icon, before a race) - (Power is shown in the big Power and Torque Graph, which can be brought up by pressing Start)
4) Replay (at the beginning of it, Power is listed along with choice of tires, among other things)

Click to expand...

Awesome post... I was always confused why few of the screens showed different figures... but I have a question...

As quoted above, you said 4 of the screens show the unit that "I" picked... choice 1~3 are the same... but choice 4 (replay) is different from choice 1~3... so which figure is correct? It always seems like replay shows less power than other screens... maybe the replay screen shows wheel HP not at the crank?

TheWizard

1) Garage Screen (where up to 10 vehicles of the ones currently possessed are listed)
2) Car Screen (screen that appears after clicking on one particular vehicle)
3) Sell Screen (screen that appears after clicking on the Sell icon)
4) Settings Screen (screen that appears after clicking on the Settings icon, before a race) - (Power is shown in the small Power and Torque Graph, top right of the screen)
5) Settings Screen (screen that appears after clicking on the Settings icon, before a race) - (Power is shown in the big Power and Torque Graph, which can be brought up by pressing Start)
6) Replay (at the beginning of it, Power is listed along with choice of tires, among other things)

Example (note I set HP as my units for Power):

Toyota Minolta 88C-V, Stage 4 Turbo:

1) 1223HP
2) 1206HP
3) 1206HP
4) 1223HP
5) 1206HP
6) 1148HP <---- this number is always lower than all other numbers... why?

Click to expand...

the replay power number appears to be the amount of power the car would make with "dirty" oil, or if an oil change was not done.

this is why you can oil change a car and have 488hp, and not be able to enter a race which requires 487 or more hp. because if you were to have the oil light come on during the series, you would technically not be allowed to race.

blurred

the replay power number appears to be the amount of power the car would make with "dirty" oil, or if an oil change was not done.

this is why you can oil change a car and have 488hp, and not be able to enter a race which requires 487 or more hp. because if you were to have the oil light come on during the series, you would technically not be allowed to race.

Click to expand...

Makes complete sense thanks! I allways thought the replay screen was the actual power reaching the ground (after drivetrain lost and flywheel lost) I guess we may be both right.

Your conversion factors aren't particularly accurate ..

1 hp = 0.7456998715822702 kW ... 1 kW = 1.3410220895950277 hp
1 ps = 0.7355 kW ... 1 kW = 1.35962 ps
1 hp = 1.01387 ps ... 1 ps = 0.98632 hp

1 kgf.m = 7.233005285 lb-ft ... 1 lb-ft = 0.138255181 kgf.m
1 lb-ft = 1.35582066 Nm ... 1 Nm = 0.7375606742 lb-ft
1 kgf.m = 9.806658 Nm ... 1 Nm = 0.1019715381 kgf.m

1 kg = 2.20462442 lbs ... 1 lb = 0.453592 kg
1 lb = 4.4482216152605 N ... 1 N = 0.224809 lbs
1 kg = 9.806658 N ... 1 N = 0.1019715381 kg

1 m = 3.280833333 ft ... 1 ft = 0.304800609601 m (1200 meters = 3937 feet)

Excellent work Wiz 👍

The only idea I have for the lower number for replays is wheel power. But even on an MR layout, its still like.. 10 to 15% power loss from the crank to the wheels...

Any ideas Famine? Good to see you pwning annoying googlers like usual

blurred

the replay power number appears to be the amount of power the car would make with "dirty" oil, or if an oil change was not done.

this is why you can oil change a car and have 488hp, and not be able to enter a race which requires 487 or more hp. because if you were to have the oil light come on during the series, you would technically not be allowed to race.

Click to expand...

sounds like a brilliant theory, Anybody has some testing to back it up?

I dont have any cars anywhere near 4000miles with out an oil change to figure it out.

2 tests could be taken

1) buy a car and with no oil change check if the replay value matches up.
2) have a car with dirty oil so that it reaches min amount of power and check if the replay value matches up.

If anybody has done or will do those tests post them in here and The Wizard will add that to his guide (giving you credit of course).

r_master78

As quoted above, you said 4 of the screens show the unit that "I" picked... choice 1~3 are the same... but choice 4 (replay) is different from choice 1~3... so which figure is correct? It always seems like replay shows less power than other screens... maybe the replay screen shows wheel HP not at the crank?

Click to expand...

That was my initial theory, but since I didn't (and still don't) have a way of backing it up with actual evidence, I didn't want to mention it in my actual guide and give misleading information.

blurred

the replay power number appears to be the amount of power the car would make with "dirty" oil, or if an oil change was not done.

Click to expand...

This is an interesting idea, too. I might do some testing later during the week, to see if this is actually reflected into the game, or if it is just another theory.

Famine

*applause*

I was about to embark upon the same thing. Glad I don't have to now. Make sure Kent knows about this for the WRS.

Click to expand...

This, coming from you sir, is a great compliment (no sarcasm implied, either). Now where is the icon that depicts a person taking his hat off and bowing slightly? Oh, I forgot. There's not one.

I will make sure Kent knows about this guide, like you suggested.

Jmac279

Your conversion factors aren't particularly accurate ..
[Lots of numbers with 15 decimal places...]

Click to expand...

I am going to say this from an Engineering point of view, and I am only going to say it once: when the game only carries 5 or 6 significant digits at the most, there is absolutely no point in using a conversion factor with more significant digits than the number being converted.

Granted, I only gave the conversion factors to three significant figures (which is less than 6 - yeah, I can do Math, believe it or not ). But that degree of precision is not needed, when in actuality the values of Power and Torque shown on the magnified version of the Graph (Settings screen) are rounded to an integer amount.

Which is promptly backed up by this:

Famine

And tell me, does anyone converting a figure with no decimal places to another figure with no decimal places REALLY care about anything past the second decimal place for a conversion factor?

Or were you just showing that you can Google too?

Click to expand...

The only reason I didn't post my answer earlier is because I am seeing this thread for the first time now, since I posted it last night.

Famine

Notwithstanding that, your conversion factor for kg to N (and vice versa) were wrong, because you didn't take into account that it's measured at sea level. On Earth.

Click to expand...

Doh! How could I miss that?!
What are we going to do with the value of Gravity? It's not constant - well, it's constant in that one particular location of the Earth where it's measured, but you know what I mean.

Should I go around the Globe and take measurements to the 30th decimal place, and then average them?

I got a ruler with which I can just do that! (yeah, it's that precise)

Azuremen

Excellent work Wiz 👍

Click to expand...

Thank you, thank you

Nice improvement, since my first super-duper useful guide on how to get zero credits in GT3, uh?

And last, but not least:

Small_Fryz

sounds like a brilliant theory, Anybody has some testing to back it up? [...] If anybody has done or will do those tests post them in here and The Wizard will add that to his guide (giving you credit of course).

Click to expand...

I will try to do some testings as soon as I have a free minute (well, free couple of hours, I should say).

If somebody comes up with ideas and has experimental data to back them up with, I will post (and give credit to) their findings in my first post, at the beginning of the page.

Thank you again, Small_Fryz, for giving me the idea that started this all thing 👍

The Wizard.

Check out this program called "Convert"
http://www.joshmadison.com/software/
I find it to be very useful. It can convert "over 250 units in more than 20 categories."

Jmac279

Your conversion factors aren't particularly accurate ..

1 hp = 0.7456998715822702 kW ... 1 kW = 1.3410220895950277 hp
1 ps = 0.7355 kW ... 1 kW = 1.35962 ps
1 hp = 1.01387 ps ... 1 ps = 0.98632 hp
ETC. ETC.

Click to expand...

Oh Step back, I forgot how much of a difference there is between 205.1723759kW and 205.2 kW Seriously, no one cares because the game is calculating it for us, and even in real life calculation I never use anything beyond 3 decimal places, maybe 4 at the most but its extremely rare.

PS, excellent thread, its interesting to know. I too noticed that the figure in the garage didnt change when I went from hp to kW (I though, thats odd I just recieved a 33% gain in power...)

63AvantiR3

Check out this program called "Convert"
http://www.joshmadison.com/software/
I find it to be very useful. It can convert "over 250 units in more than 20 categories."

Click to expand...

If you want a really good place for converting quantities from one set of units to another, this is the place:

Online Conversion

It converts everything to everything...
And you don't need to download any software

The Wizard.

blurred

the replay power number appears to be the amount of power the car would make with "dirty" oil, or if an oil change was not done.

this is why you can oil change a car and have 488hp, and not be able to enter a race which requires 487 or more hp. because if you were to have the oil light come on during the series, you would technically not be allowed to race.

Click to expand...

This is a very good theroy and I think it is true. I was racing my M3 without oil change for about 700 miles now and the replay screen showed 482 HP consistanly, but the other screens showed less power than before! More extensive testing should be done, but it is a very good start

I think this should be added to the look here thread.

Its very informative and TheWizard deserves some credit for it.

Very helpful guide 👍

Nice work 👍. Any chance of this becoming a sticky thread mods?

I think I have figured out why the power figure shown in 6) (Replay) does not agree with the ones shown in 2), 3), and 5) (Car Screen, Sell Screen, and Settings Screen - big Power and Torque Graph, respectively).

I am testing my theory right now.

I will update the first post of this thread with the results, whenever I finish checking a few more particulars here and there.

More to come later.

The Wizard.

Well, I hate to double post, but if I don't nobody will see this (GT4 threads get recicled faster than one can post ).

I just updated the first post, with the new information I acquired after two days of extensive testing.

It explains why the amount of power shown on the Replay screen is so much different than the values shown elsewhere.

If you are too lazy to read the whole thing, just read the last Summary - it is all well summarized there

It can be found under the Red Big Bold UPDATE heading (really? )

Any comments are welcome.

The Wizard.

TheWizard

Any comments are welcome.

The Wizard

Click to expand...

The Wizard deserves a big pat on the back for getting this straight.

I didn't see any follow-up to understand why PD would use PS so consistantly and not some other unit of measure. Weird...

Cheers,

Thanks for the appreciation, MasterGT 👍

Also, about PD using PS so consistantly, well - guess what?

I have just found another place where the units used are independent on the units chosen:

The "Tune Shop", in the Car dealer section and the "Tuner Village", on the map.

Even if it shows 'Before xxx HP ---> After yyy HP' (assuming you have HP chosen as your units for Power), the value shown is in - you guessed it - PS.

Weird indeed

EDIT: I will add this information in the first post of this thread later.

The Wizard.

Excellent stuff ... this has had me buggered for ages!!

CHEERS!!!

What power figures does PD give the AI cars when calculating the A spec points?
Since PD has been driving them for over 3 years I guess it would be the number given for over 8500 miles. Can anyone confirm?

Good question, Uncle Harry. I never did think about checking that aspect.

I just booted up my PS2 and I thought the quickest way to check this was to go to the only race I know where I can find another MINOLTA Toyota 88C-V Race Car '89: Professional Events - Gran Turismo World Championship.

I previewed the race (Tokyo R246, to be precise) and sure enough, there was the MINOLTA Toyota 88C-V Race Car '89, listed as having 906HP.

Therefore, my conclusion is that (whether the vehicle is stock or not) the amount of power shown in the race preview is the one the vehicle would have at >8500 miles.

So, I would assume they compare the power of the vehicle entered (which is still the value at >8500 miles, I would assume, since that is what is shown on the Replay screen) to the power the other vehicles have, still at >8500 miles (since that is what they are shown to have in the Preview screen).

I will update the first post with this information as well, later.

The Wizard.

woah..someone who spent the time to find out about all the stuff..i was wondering..lol..some good stuff

Great stuff Wizard, this has cleared up a lot. 👍

It makes sense that the figures are in PS, as PS is the standard for measuring power in Japan. When PD were developing the GT4, they probably worked with PS, then converted it later at the end. Maybe they forgot or were too rushed to convert all the areas where power is displayed, hence some of the numbers are PS no matter what unit you choose.

One final question though, and I'm not sure how to figure this out short of asking PD directly - Are the figures quoted in the game (be they PS, KW, HP or whatever) at the flywheel or at the wheels?

Any ideas?

Once again, a great writeup Wizard. Well done.

ferrari_chris

Great stuff Wizard, this has cleared up a lot. 👍

It makes sense that the figures are in PS, as PS is the standard for measuring power in Japan. When PD were developing the GT4, they probably worked with PS, then converted it later at the end. Maybe they forgot or were too rushed to convert all the areas where power is displayed, hence some of the numbers are PS no matter what unit you choose.

One final question though, and I'm not sure how to figure this out short of asking PD directly - Are the figures quoted in the game (be they PS, KW, HP or whatever) at the flywheel or at the wheels?

Any ideas?

Once again, a great writeup Wizard. Well done.

Click to expand...

Its at the flywheel.

Very nice work. After having my mem card stolen and having to restart I decided to use kW for power (as used in oZ) so the discrepancies were magnified. Particularly irritating when trying to enter the Supercar Festival (ok, spent more money, now have extra 100kW, still can't enter? wtf! Spend more money...) - which has just made me think, what value is this race using to allow entry - is it the actual power or the old and knackered power? I will have to check it out when I do this series.

MasterGT

I didn't see any follow-up to understand why PD would use PS so consistantly and not some other unit of measure. Weird...

Cheers,

Click to expand...

I get the funny feeling that PS is the standard measurement of power for Japan, it's used in the BMI series and in other online videos with japanese subtitles that i've seen. Just an idea, im not sure.

volkuro

I get the funny feeling that PS is the standard measurement of power for Japan, it's used in the BMI series and in other online videos with japanese subtitles that i've seen. Just an idea, im not sure.

Click to expand...

Yeah, PS is the official unit of power in Japan.

onedarkhorsee

It's at the flywheel.

Click to expand...

That sounds awfully definative, how can you be sure?...

Not much to add here, except this thread answered a lot of my questions. Thanks, TheWizard! I'm setting it all to PS now, since the power thing has bugged me since Day 1 (well, I actually didn't race until Day 2).

Also, I've seen many avatars since I've been here, and yours definately wins first prize!