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Honda / Acura is restating all it's horsepower and torque ratings for the 2006 model year to come into compliance with Society of Automotive Engineers (SAE) J1349 (Rev 8/04) net calculations.

For example: The 2005 Acura MDX was rated at 265 HP @5800 RPM, and 253 lbs-ft of torque at 3500 RPM. There are apparently no changes in the MDX engine for 2006, but the horsepower and torque ratings have been restated to 253 HP @ 5800 RPM and 250 lbs-ft. of torque at 3500 RPM.

Our Ridgeline's are rated at 255 HP @ 5750 RPM, and 252 lbs-ft of torque at 4500 RPM.

Are our Ridgline numbers calculated by the SAE J1349 methods?

Will Honda restate the Ridgline numbers lower very soon?

If our numbers are already calculated the new way it would mean our engines are higher horsepower than the MDX which recommends premium fuel.

Anyone have any ideas on this?
 

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Discussion Starter #4
Honda still lists the 255HP number on their web site. Anyone know where I can verify the 247 HP figure?
 

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I seem to remember a similar issue a few years back with another automaker. The owners of the vehicles, when they found out of the "new" horsepower numbers, got really pissed. I think they were offered by the manufacturer to buy their vehicles back or something. Anyone else remember ?
 

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rtpjunior said:
I seem to remember a similar issue a few years back with another automaker. The owners of the vehicles, when they found out of the "new" horsepower numbers, got really pissed. I think they were offered by the manufacturer to buy their vehicles back or something. Anyone else remember ?
I remember that Ford had to buy back some vehicles when it was discoverd that Ford had completely misstated the horsepower figures. That wasn't a case of using a new method... they made computer changes that reduced the horsepower but never stated the true lower horsepower ratings.
 

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csimo said:
I remember that Ford had to buy back some vehicles when it was discoverd that Ford had completely misstated the horsepower figures. That wasn't a case of using a new method... they made computer changes that reduced the horsepower but never stated the true lower horsepower ratings.
Was this the Mustang? I seem to remember there was a big hullabloo about the liter rating (and horsepower? - not sure).
 

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There's a difference in this situation. In the Mustang and Miata situation, both engines were rated for x but when people started to put the cars on the dyno, they never were able to produce those numbers.

Here, the situation is that SAE changed the standard on which the engines are dyno'd by the mfg to get their advertised rating. This had led to new power ratings.
 

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DoctorJ said:
All manufacturer's ratings for HP and torque are at the crank of the engine. So you will never reproduce the numbers at a wheel dyno due to the loss through the drivetrain. What you can expect from a wheel dyno is about a 20% loss for automatic transmissions and 15-18% for manual transmissions.
Actually, horsepower was measured at the crank until the mid-late 1960s, when the more current standard for rating horsepower at the rear wheels was developed (no front wheel drive cars in mass production yet). This latest reworking of the measuring systems continues to measure horespower at the wheels.

Ford got dinged in the 1960s with the Mustang because it was advertising horsepower from the crankshaft, and not from the rear wheels. It was after that the industry began measuring from the wheels.
 

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All advertised horsepower ratings you see today are not that of wheel HP. They are all measured on an engine dyno with accessories(alternator, etc) attached.
For example: an RSX is(was) rated at 200hp, this is not wheel hp. The wheel hp as seen on dynjots average between 165-175hp.

The problem with the recent miata and mustangs deal was that even when you took into account the generally accepted drivetrain losses, the numbers still came up short.
 

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This is a lengthy read but should suffice for anyone not wanting to do the research. This is copied and pasted from http://www.musclecarclub.com/library/dictionary/engine-terms.shtml

SAE Gross Horsepower or Brake horsepower (bhp) was the standard horsepower measurement by the automotive industry up until 1971. Brake Horsepower Power is measured at the flywheel with no load from a chassis or any accessories and with fuel and ignition operations under ideal conditions. An accessory is anything attached to the engine, by any means, which is not required for basic engine operation. By this definition, this would include a power steering pump, smog pump, air conditioning compressor and an alternator. Ideal conditions, often called laboratory conditions, are standardized settings for use during horsepower measurement. During the 1960s they consisted of a barometric pressure of 29.92 Hg and a temperature of 60 degrees F.

SAE Net Horsepower became the standard measurement in 1972, and is still used today. SAE Net horsepower is the horsepower generated by the engine at the flywheel with all accessories attached. This change was made to reflect the numerous energy sapping accessories that cars began to have, such as an A/C Compressor and alternator, and thus was a better representation of the actual power generated by the engine. This number is always lower than the SAE Gross horsepower. Therefore, the same engine could have been rated in 1971 as 360 SAE Gross Horsepower and in 1972 as 300 SAE Net horsepower without any reduction in "power."

Wheel horsepower is horsepower measured at the actual drive wheels, taking into account the load from the chassis and all accessories. It is the most accurate measure of the amount of energy that the car actually generates to move it forward. Wheel horsepower is measured using a dynamometer. This is done by placing the vehicle's driven wheels on a large roller and accelerating the wheels up to redline in first or second gear. The vehicle's ability to turn this roller is measured and calculated (formula below) to come up with a figure that represents how much horsepower is actually available to move the vehicle around. Because a frictional loss between the engine and the driven wheels is unavoidable, wheel-driven horsepower will always be less than SAE Net Horsepower. How much less wheel-driven horsepower will depend on how many mechanical parts exist between a vehicle's engine and its driven wheels. This is usually measured as a percentage loss due to the "friction" of the intermediate components between the flywheel and the actual wheel. For a Rear Wheel Drive car, engine power has to travel through a transmission, driveshaft, rear-differential, and two axle shafts (one for each rear wheel). That's four separate mechanical components taking a bite out of the car's horsepower before the rear wheels even begin to turn. Front-wheel drive cars with transverse-mounted engines usually have a lower frictional loss because horsepower only has to travel from the engine, through the transmission and down two short driveshafts before reaching the wheels. Typical "powertrain" losses run between 15-22% but vary greatly between cars.

Hope this helps.
 

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Great post Methodtim
 

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Not sure where I've been. I just noticed the new rating by accident when I saw the RL advertised this week in a magazine. Then I checked Honda's website and saw the updated numbers. Kind of irritating that they changed it, but at least I still got what I was expecting...even though they measure it differently.
 
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