Toyota's MZ series engines, which were used in the previous Camrys that saw the biggest losses are known to have oversensitive knock sensors. SAE J1349 mandates engine testing with the required fuel octane rating, not the manufacturers recommended fuel octane. All of Toyota's engines require 87 octane, and the high compression engines, like the MZ series, recommend 91+ octane.
For example:
Toyota 3.3L, Camry (87 octane):
210hp/220lb-ft (-15hp, -20lb-ft)
They are the exact same engine, mechanically and electronically. But because of the 10.8:1 compression ratio in both the 3.3L and 3.5L, running 87 octane results in a significant power loss.
So:
1) Use 91+ or higher on engines with a compression ratio above 10.0:1 or if the manfacturer recommends it.
2) The SAE J1349 revised ratings have no effect on WHP numbers. The engine still produces the same amount of power when using the optimum octane rating.
3) Knock sensors will decrease the performance of every engine when detonation is detected. The likelihood of detonation increases with compression ratio and certain engine designs. The more compression an engine runs, the more power you will lose when using an easily ignitable fuel, such as 87 octane.
SOme of it has to do with the gas that they run through the engine while the test is being done. From what I can gather they list HP ratings according the the premium fuel. However if the car does not require premium then they can not list tht Hp rating. SO if a car running premium produces 200 Hp and the same engine running regualr produces 195 they have to lsit the 195.
However it also has to do with what accessories are being run at the time the test is done also. I think now they are required to run certai naccesseroies whereas before they were not required to. Like PS and alternator and things like that that can cause a drag on the engine.
this is what I have come to gather anyway.
As for the HP rating of your car it all depends on how you want to looka t it. If you go by the old way of testing hten yes you have 103 but if it were to be tested using the new standards then it could be but not absolutely be lower. In some cases as with the Domestic manufacturers it has actually gone up in some instances.
It is not really a matter of lying inteh past it was more or less bending the rules.
also the Hp rating that we get from manufacturers are at the flywheel. SO if you were to get your car tested ona Dyno it wouldprobably be anywhere from 10--20% lower than what the HP rating is according to any SAE testing. HTis is due to the loss you get through the drivertrain.
Thanks for the response. I have another question So now the engines that are tested under the new standard to start with, does this mean they actually produce more horespower than what is stated? Meaning, like you said, now they require accessories to be run or some of them, obviously this yields the engines optimum or max output. So if my reasoning is right, the new Camry, RAV4 as well as the Avalon really produce 280? Is that correct? But sense its not the egine alone, it measures driveline loss? Like the new Yaris is rated 106 under the new standards, could this mean it actually produces more? I know there is some margine of error but its mostly accurate right? So does this mean with new EPA rates that I heard are coming out, they will run accessories as well to get more of an accurate milage? Thanks for any response and patients with me-newbie! I'm just curious about it.
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well in all technicality, the entire curve is effected...but at the same time, performance doesnt change b/c everything is installed on the car when you drive it anyway....so its really just splitting hairs and people complaining about it.
i meant the shape of it. my preference: a nearly flat torque curve =
but sadly, america's ignorant consumer doesnt understand the meaning of rated horsepower. for the engineers, rated means the engine is tested under no load conditions. but then again, its not engineers who buys these cars.
What a rip-off, not getting the horsepower you paid for. Another issue is fuel economy, the Japanese brands tend to lie too, the Fuel Economy testing need to be updated too. I wouldn't be suprised if the Japanese Cars will have lower fuel economies with a new test.
I enjoy my Japanese Car, but wished they told the truth. I feel like they cheated.
What a rip-off, not getting the horsepower you paid for. Another issue is fuel economy, the Japanese brands tend to lie too, the Fuel Economy testing need to be updated too. I wouldn't be suprised if the Japanese Cars will have lower fuel economies with a new test.
I enjoy my Japanese Car, but wished they told the truth. I feel like they cheated.
I can understand your subjective feelings, but then again your statement is incorrect (and fuelled by misinformation) and you didn't know half of the story. Japanese manufacturers don't lie about the fuel economy of their products, but the implementation of the government-regulated EPA fuel efficiency rating DOES. I've read an article a while back where many consumers found the EPA ratings on a Toyota Prius to be way too optimistic, and Toyota's response is that it is due to having to list the EPA rating (which is tested under VERY IDEAL situation such as A/C off and driving under very light load, etc) which is the law, instead of Toyota's OWN fuel economy rating which would yield lesser fuel economy than EPA but would reflect more realistic driving conditions. So in short, Toyota would have preferred to show their own fuel efficiency ratings which would be more realistic for consumers to decide, but they can't and must display EPA ratings instead because it's the law that said so.
Hope that clears up any ignorance, confusion and frustration.
So if my reasoning is right, the new Camry, RAV4 as well as the Avalon really produce 280?
Maybe, if you used premium fuel and leave all accessories off you might get close to 280 but then take into account drivetrain loss but either way, the relative hp boost might be there.
This new standard is no different from the change made in the 70s when manufacturers were made to publish net hp rating instead of gross... so your 400hp Charger from the 70s didn't really produce 400hp.... well it did at the flywheel but not after drivetrain and accessory add ons. Do you feel cheated? or would you continue to assume it has 400hp because that's what it said in the brochure? Same reasoning.
As for fuel economy, all manufacturer's are only allowed to publish EPA ratings. This evens the playing field so that everyone gets tested under the same condition even though it may not be ideally real-world type situations. Either way, the figures are meant for comparisons. This means, Car A with better mileage will, on average, get better mileage than Car B if driven by the same driver, over the same route. Or heck, even with different drivers over the same route (assuming one isn't like lead footed and the other an 80-yr old lady).
e.g. The Prius vs. Civic Hybrid comparo that Canadian Driver is doing right now. Yeah, it's winter with snow and cold temps (they must've done it in Dec or Jan), but so far, the Prius is getting better mileage than the HCH just like EPA said. They're not close to the EPA rating, of course but in relative terms, EPA is right.
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If you look at wheel horsepower, it's the same with either rating. You can calculate the new rating's WHP by using 12% drivetrain loss, and the old rating with around 15-15.2% drivetrain loss.
i meant the shape of it. my preference: a nearly flat torque curve =
but sadly, america's ignorant consumer doesnt understand the meaning of rated horsepower. for the engineers, rated means the engine is tested under no load conditions. but then again, its not engineers who buys these cars.
I completely agree with you, just not many people know how to interpret numbers. They see the article titles and say "hey, im getting ripped off", which really bothers me.
It can be confusing from different aspects b/c of the two places the rating changes come from(from my understanding)
1) octane. If you run 93 on the 3.5L engine you should be getting 280hp. It just bugs me now that you wont know what some engines will run on 93 b/c they have to adverstise with 87.
2) accessories. even if you ran premium like above....you still probably wouldnt get the 280 b/c they ahve to test with the accessories on now....so there still is more of a "loss", that is cancelled out once the engine is in the car anyway.
What they should do is all use the same kind of dyno and dyno a car then, and publish those wheel horsepower numbers....but then the entire population would be wondering why they have 30 less horsepower
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So now the engines that are tested under the new standard to start with, does this mean they actually produce more horespower than what is stated? Meaning, like you said, now they require accessories to be run or some of them, obviously this yields the engines optimum or max output. So if my reasoning is right, the new Camry, RAV4 as well as the Avalon really produce 280? Is that correct? But sense its not the egine alone, it measures driveline loss? Like the new Yaris is rated 106 under the new standards, could this mean it actually produces more? I know there is some margine of error but its mostly accurate right? So does this mean with new EPA rates that I heard are coming out, they will run accessories as well to get more of an accurate milage? Thanks for any response and patients with me-newbie! I'm just curious about it. 
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