SAE revises engine rating process

[WillErickson]

Has anyone been following this news? Apparently the SAE has revised its process for an engine's power ratings. GM has agreed to adopt this new process, it appears that Honda/Acura will as well. I'm curious to see if all manufacturers will adopt the new system and have all their engines rerated. The following is some info I pulled off a consumer reports forum:

It appears with the exception of the TSX, all the Acura's horsepower ratings is lower according to the SAE. Here are the following results regarding the Acuras:

Acura rating SAE rating

MDX 265 253

RSX 210 201

TL 270 258

TSX 200 205

RL 300 290

Another car that was originally rated at 440 horsepower, The Cadillac STS-V was found to have 469 horsepower by the SAE.

With these new horsepower ratings is CR going to revise what the manufacturer states is the horsepower of the vehicle to what the SAE finds or stick with the manufacturer claims? (end quote)

The only model that has been updated and listed as a 2006 model on honda/acura's website is the RSX, which is advervised with the new 201 hp rating (Type S). The base car has also been rerated to 155 hp (from 160).

It'll be interesting to see if all manufacturers follow suit, and where other engines come out.

Will

 

[satan_srv]

what about the NSX?

 

[White92]

There is a large article on changes for the 2006 Acura line up on vtec.net. Here's a link to it. http://www.vtec.net/news/news-item?news_item_id=384913

Here are pieces of it.

For the 2006 model year, all Acura horsepower and torque specifications have been updated to reflect revised Society of Automotive Engineers (SAE) J1349 (Rev 8/04) net calculations that went into effect in January of 2005. These new calculations reflect a number of significant changes in the way horsepower and torque are measured and may cause SAE net horsepower and torque totals published in 2006 media materials to differ from the figures published in previous years. To avoid confusion, all 2006 Acura press materials will specify “SAE net (Rev 8/04”) after all horsepower and torque figures to denote adherence to the new standards

The NSX is not listed, although all other models are.

 

[WillErickson]

what about the NSX?

Since there is no 2006 NSX, it likely won't be tested. I'm sure many would like to know how it would have rated.

Will

 

[NetViper]

I am sure Caddy was anxious to adopt them as it makes their cars look better. From reading Autonews, there are many other companies that have no committted to it yet because it lowers their HP and TQ numbers. As far as I know, they are not forced to use it either if they do not want to.

 

[WillErickson]

I was just checking various automakers websites, Toyota has info up for 2006 models, with new ratings. All models appear to be rated lower, by as much as 20 hp (V6 Camry).

Will

 

[White92]

I'm curious to see what the RX-8 will be rated at with SAE numbers. From what I've heard, they've had problems with overstated hp numbers.

 

[NetViper]

I'm curious to see what the RX-8 will be rated at with SAE numbers. From what I've heard, they've had problems with overstated hp numbers.

They already lowered the RX-8 once from 250 to 238HP. That car needs a serious bump in HP. The long term review in the latest C&D was pretty dissapointing.

 

[White92]

They already lowered the RX-8 once from 250 to 238HP. That car needs a serious bump in HP. The long term review in the latest C&D from pretty dissapointing.

Seriously. The RX-8 is nothing like the RX-7 was. Kind of like how the 350Z is nothing like the 300ZX TT.

 

[satan_srv]

So...what kind of motors benefit from the revision vs. are hurt? Or are we talking too many factors here?

 

[ADNOH]

So...what kind of motors benefit from the revision vs. are hurt? Or are we talking too many factors here?

From the HP ratings of the Caddies and Acura I'm guessing the ratings of larger displacement engines will stay the same or even go up and for lower displacement engines the ratings will drop.

 

[dynatac]

A bit OT:

I forgot where I saw this, it may have very well been here, but there's a video out there somewhere that shows how misleading HP/dyno tests can be.

The video is done by Dinan at their in house dyno.
They use a 5 series, strap it in and do some runs. Results are as expected.
The next run consists of opening the hood. Results in HP are minimal but noticed.
Finally they bring in a huge fan and place it in front of the car. Significant gains are noticed.

Then they beg the question - Well? Which run do you use as your claim that the engine makes XXX HP?

The point Dinan was trying to make was that there are various external factors that go into the engine's power rating. Like outside wind... :biggrin:

 

[WillErickson]

True, there are many factors that affect a car's horsepower at the wheels, but the automakers are measuring power at the flywheel, under a more controlled environment. The way I read into the new process is that previously each company used their own standard for "controlled environment" (air temp, which engine accessories run, altitude correction factor, etc.). Now, to get SAE certification, you must use their set of standards, as well as have them witness the process.

Will

 

[NSX-Racer]

Since there is no 2006 NSX, it likely won't be tested. I'm sure many would like to know how it would have rated.

Will

My guess is that this new SAE rating comes closer to the european DIN PS. Which would mean 274 for the pre 2001 model and 280 for the newer ones (isn't the NSX rated with 290 hp in U.S.?).