Is250 Power Curves? (hp & Torque)

[pghanna]

Has anyone seen actual curves for the horsepower and torque performance? On the Lexus site the "Performance and Technology" video states that the IS250 has 90% of its power between 1800 and 6500 RPM. these seem to be harder to find recently.

[Gaugster]

Has anyone seen actual curves for the horsepower and torque performance? On the Lexus site the "Performance and Technology" video states that the IS250 has 90% of its power between 1800 and 6500 RPM. these seem to be harder to find recently.

Here is what has been passed around from others.

http://lexus.jp/models/is/performance/engine/4gr-fse.html

I attached the graph incase the link doesn't work in the future. Also keep in mind that this is the JDM version so the numbers are slightly higher when converted to HP/TQ. Presumable from using higher octane full or some other small difference from the JDM.

[Randy&Bonnie]

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[Gaugster]

Has anyone seen actual curves for the horsepower and torque performance? On the Lexus site the "Performance and Technology" video states that the IS250 has 90% of its power between 1800 and 6500 RPM. these seem to be harder to find recently.

Isn't that statement "90% of its..." a little misleading? Most engines develop peak torque at a specific RPM or very narrow RPM range. 1800 to 6500 RPM range is practically the entire power band.

Randy

I think the original attribute that Lexus was boasting about was that 90% of the torque (not power) was available starting at around 2k. Basically that the engine has wide torque curve.

[Randy&Bonnie]

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[bartkat]

The IS250 is powered by a 2.5-litre quad cam 24-valve V6 engine, which develops 153 kW at 6 400 r/min and 252 Nm of torque at 4 800 r/min.

The torque curve is very flat with virtually all its torque available from 2 000 r/min all the way to 6 000 r/min. The free-revving V6 is refined but when you are in need of a bit of "oomph" it is a bit flat.

http://www.wheels24.co.za/Wheels24/RoadTes...2046716,00.html

[EnginePassion]

The IS250 is powered by a 2.5-litre quad cam 24-valve V6 engine, which develops 153 kW at 6 400 r/min and 252 Nm of torque at 4 800 r/min.

The torque curve is very flat with virtually all its torque available from 2 000 r/min all the way to 6 000 r/min. The free-revving V6 is refined but when you are in need of a bit of "oomph" it is a bit flat.

http://www.wheels24.co.za/Wheels24/RoadTes...2046716,00.html

Good post bartkat.

Those journalists write but they never drove this IS for a month or two so their judgement is not to be relied upon (to say the least). The thing that I hate most is lying/misleading, I consider myself been mislead that this IS250 yields 204 hp at 6400 rpm. The car is 3700 pounds. It looks good from front and back; however, from the sides it is ugly. Poping, rattling, squeaking throw it out of any luxury car category. How could Lexus keep producing it for three consecutive years without fixing these consistent/persistent same problems? I don't care who makes my car, what I care about is performance quality. I am not sure what will be the conditions of this car at 60K miles? I am sorry if I sound aggressive but hope that you guys understand that our expectations were not met.

[Gaugster]

I will have to see a certified dyno test to believe that engine has a 90% of it's peak torque value "available" between 1800 and 6500 RPMS!! It may have a wide torque curve, but that's a little hard to believe!

Randy

I think that between Bartkat's post and mine, we have this one nailed down very well. I am sure the Lexus.jp information was certified and the third-party information that Bartkat showed just confirms it.

While the IS250 is by no mean a torque monster, it does have power in the lower RPM's, which is still impressive for a 2.5L

Regards,

[Randy&Bonnie]

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[Knightshade]

http://my.is/forums/f167/is250-350-headers...oup-buy-350501/

IS250 dyno before/after the mazzuri header in that thread

Looks like peak torque is 160 for the no-header one... 90% of that would be 144 and it was at or above that from 1800 onward. So claim looks pretty valid.

[Randy&Bonnie]

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[Gaugster]

Well, I would encourage you to get your car dyno'd and post the results. It’s a little hard to get numbers below ~2700rpm with the auto tranny but the My.IS was a manual. We can never have enough info about these cars so I am all for it. A few points though.

1 - Keep in mind that the graph from Japan is measured at the crankshaft of the engine and not the wheels like the graphs from My.IS. Both are valid IMO but I just want to point out the difference.

2 - Never trust the seat-of-the-pants dyno. It all over the internet but the basic idea is that the human body is better at "feeling" changes to torque output. So a level torque curve looks good for graphs but doesn't have the same emotional response that happens when a big boost in power happens. That seems to be why so many people seem addicted to 'boost' etc...

Regards,

[bartkat]

http://my.is/forums/f167/is250-350-headers...oup-buy-350501/

IS250 dyno before/after the mazzuri header in that thread

Looks like peak torque is 160 for the no-header one... 90% of that would be 144 and it was at or above that from 1800 onward. So claim looks pretty valid.

Yep, I did some checking myself and I do believe the chart could be reasonably accurate. I'd still like to see an independent test performed with my own eyes. But for now I'll accept the published data. For the record, my "seat-of-the-pants" dyno doesnt' agree with that test.

Randy

Go run your own dyno and post it up here.

[smooth1]

I keep rereading your posts. You say you were misled? What into buying a 250 instead of a 350? I don't know what you thought 204 peak hp is supposed to feel like, ( that would be crank hp, not rear wheel.) The IS 250 I allways thought was the "gas miser" version and the 350 was the "sport" version. Where you just confused?

[Randy&Bonnie]

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[bartkat]

We're pretty much just common folk here.

[Knightshade]

90% of not much torque is still not much torque.

[EnginePassion]

I keep rereading your posts. You say you were misled? What into buying a 250 instead of a 350? I don't know what you thought 204 peak hp is supposed to feel like, ( that would be crank hp, not rear wheel.) The IS 250 I allways thought was the "gas miser" version and the 350 was the "sport" version. Where you just confused?

It suffices to say this is not the "Pursuit of Perfection" as it was claimed.

204 hp is a lot if a car is really equpped with a 204 hp you'd feel it. Peak? You would not get 204 even if you rev the engine up to 7k rpm. I may sound odd to you but still entitled to say my opinion and I am always against fraud.

[Gaugster]

Hey Randy,

Again, welcome to the club. Sorry if it seemed like we bombarded you with charts and data and stuff. I am an Electrical Engineer by trade and hence do things very methodically. There is so much ‘non-fact’ out on the internet so I always like to post as much truth/data as I can.

I admire that you could just walk in to a car dealer and pick a car and take it home. I could never do such a thing without hours of research etc… I just not my M.O.

[Knightshade]

I keep rereading your posts. You say you were misled? What into buying a 250 instead of a 350? I don't know what you thought 204 peak hp is supposed to feel like, ( that would be crank hp, not rear wheel.) The IS 250 I allways thought was the "gas miser" version and the 350 was the "sport" version. Where you just confused?

It suffices to say this is not the "Pursuit of Perfection" as it was claimed.

204 hp is a lot if a car is really equpped with a 204 hp you'd feel it. Peak? You would not get 204 even if you rev the engine up to 7k rpm. I may sound odd to you but still entitled to say my opinion and I am always against fraud.

As long as you understand your opinion is wrong.

The car has 204 crank hp.

If it didn't, there'd have been lawsuits.

See also when Mazda had to buy back peoples RX-8s because they lied about horsepower, other companies have been through the same.

The butt dyno is a reliably horrible way to know the actual power of a car. An -actual- dyno tends to work better.

[smooth1]

I keep rereading your posts. You say you were misled? What into buying a 250 instead of a 350? I don't know what you thought 204 peak hp is supposed to feel like, ( that would be crank hp, not rear wheel.) The IS 250 I allways thought was the "gas miser" version and the 350 was the "sport" version. Where you just confused?

It suffices to say this is not the "Pursuit of Perfection" as it was claimed.

204 hp is a lot if a car is really equpped with a 204 hp you'd feel it. Peak? You would not get 204 even if you rev the engine up to 7k rpm. I may sound odd to you but still entitled to say my opinion and I am always against fraud.

Well, I don't think it's Lexus' fault that you don't understand the mechanical application of hp and torque. All manufacturers state horsepower created at the flywheel, or crank horsepower as it's called in the garage. As the motor produces hp, and sends it thru the torque converter, then thru the transmission, then down the drive shaft, thru the differential, and to the rear axles, the most usable horsepower and torque numbers are produced there. But typically you see a 15-20 % loss of hp from the crank to the rear wheels. Every dyno run and sheet I have seen on the IS 250 falls right into that. I think your expectations of a 2.5 liter is just not founded by any facts. The IS250 was marketed to look good, and get better gas mileage. The IS 250 does 0-60 in 7.5 seconds, which by the way is .2 seconds faster than the Audi A4 Turbo!, and does the 1/4 mile in 15.8 seconds, which is tied with the A4 Turbo. While the A4 has a nice mid RPM pull once the turbo spools up, the IS 250 does have a very wide torque curve. Also, Never be overly concerned with the peak hp number. That number is only produced for about a second or 2 before you shift to the next gear, The bigger, more important number is the average hp number. And the weight of the car. Those are the better numbers to go by. And once you see that the IS 250 produces a 130 average hp ( which is the real everyday driving number, then you would have gotten a much better scale for the butt dyno to judge to). Let me break this down further. A 2 liter 4 cylinder engine, that produces 250 hp, a 3 liter V6 that produces 250 hp, and a 4 liter V8 that produces 250 hp. If they were all put in equal weighted vehicles, do you think they all would be equally fast? I'll give you the 2 liter, and I'll take the 4 liter, and we can go and race.

Edit*- I just found this: http://www.edmunds.com/apps/vdpcontainers/...28/pageNumber=2

Are you not getting these performance numbers?

[smooth1]

I keep rereading your posts. You say you were misled? What into buying a 250 instead of a 350? I don't know what you thought 204 peak hp is supposed to feel like, ( that would be crank hp, not rear wheel.) The IS 250 I allways thought was the "gas miser" version and the 350 was the "sport" version. Where you just confused?

I'm not sure what point you are trying to make. Do I detect just a hint of sarcasm in your post? Do you want to know if I was "misled"? .... into buying a car? It's not "Where" I was misled. Perhaps my comments were "misleading" to you. What part of my comments do you think I'm "confused" about? If you are truly interested, at the time I purchased the IS250, I had about $75,000 in my checking account as was prepared to buy whatever car my wife wanted. We had lunch that day. We noticed an eye-catching red IS250 parked right next to us. I said "Gee, Honey, you'd look great driving that little Lexy! She said "No, I think the backseat is too small." We drove off, within a few minutes, she said "Isn't the Lexus dealer right down the street?" I said "Yes". She said "Let's stop in." We pulled up to the front door of the dealership and parked right in front was the car we bought that night. It was purely her decision, and she didn't even test drive the car. Within 30 seconds of me driving the car, I said "This is not as peppy as I thought it would be and I would go for the 350! She said "Great, then this one will be perfect for me!"

Now regarding my comment about the post with "90% of it's..", when I first read it I thought, "Gee, that sounds like an engine I would want in my car! But, it still seemed a wee bit exaggerated. Is it OK to feel that way? Perhaps I'm not quite up to speed with the "experts" on the subject. I suppose if it weren't for guys like me.... you wouldn't look so smart!

Randy

I am not being sarcastic in the least. When I am, it's very obvious. ;)

I was trying to figure out what your real concern is, and what your questions are. They seem very diluted in useless information, and confusing. Are you saying that the IS 250 isn't as fast as the hp number would seem to indicate? Or are you even asking a question?

Within 30 seconds of me driving the car, I said "This is not as peppy as I thought it would be and I would go for the 350! She said "Great, then this one will be perfect for me!"

So the wife is happy with the car and you are not? Or did she mean the 350 also? What does how much money you have in your checking account have anything to do with the performance of the IS250 or IS350? Are you upset that you bought a car without doing any research and now feel a little let down? or upon discovery maybe some buyers remorse?

Again, not being a smart a$$, just trying to figure out what your really saying here. :)

[CrunchySkippy]

Smooth1 - you lost me with this part:

Let me break this down further. A 2 liter 4 cylinder engine, that produces 250 hp, a 3 liter V6 that produces 250 hp, and a 4 liter V8 that produces 250 hp. If they were all put in equal weighted vehicles, do you think they all would be equally fast? I'll give you the 2 liter, and I'll take the 4 liter, and we can go and race.

Maybe its the definition of "fast" (top speed vs. acceleration)?

EDIT - I thought more about this: Are you saying that 8 cylinder engines *typically* make more HP throughout the range (usuable) than, say 4 or 6 cylinder engines?

On another note, didn't the Acura TL (circa 2004) originally state it had 300HP and then had to give rebates to original owners and restate it as ~270HP?

[smooth1]

Smooth1 - you lost me with this part:

Let me break this down further. A 2 liter 4 cylinder engine, that produces 250 hp, a 3 liter V6 that produces 250 hp, and a 4 liter V8 that produces 250 hp. If they were all put in equal weighted vehicles, do you think they all would be equally fast? I'll give you the 2 liter, and I'll take the 4 liter, and we can go and race.

Maybe its the definition of "fast" (top speed vs. acceleration)?

EDIT - I thought more about this: Are you saying that 8 cylinder engines *typically* make more HP throughout the range (usuable) than, say 4 or 6 cylinder engines?

On another note, didn't the Acura TL (circa 2004) originally state it had 300HP and then had to give rebates to original owners and restate it as ~270HP?

Typically, yes. There's nothing like cubic inch horsepower. Even turbos and superchargers are a different kind of horsepower.

Look at this dyno sheet:

Notice that the torque starts at around 240 ftlbs., and remains relatively flat all the way across the rev range. This is how they can just drop the gas pedal and break the tires loose in a white screaming cloud line.

Now look at this one:

even though this car is producing about the same total hp and torque, it doesn't even break 100 hp until well after 4k rpm. And the torque comes in about the same. So, so long as this car can keep the revs between 4500 and 6500 rpms, then both cars would be pretty close, but on the track or dragstrip, or real world driving, the Mustang has a full rev range at it's disposal, and that kind of advantage just can't be overcome.

Now before I hit the send button on this, let me say there are some exceptions to this rule. But they are few and far between. I'm not talking about highly tuned race motors and exotic engineering wonders.

Which by the way is one of the reasons the IS 350 V6 motor is one of the nicest to come out of Lexus. For a 3.5 liter motor, look at the torque!! and it builds hp very quickly!

[smooth1]

Oh, and for your own comparisons and enjoyment, here is the dyno run of an IS250: