Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

At least Briggs has all this in writing on their website it you know enough to look for it.  Obviously Tecumseh and any other engine manufacturer follows this same rating procedure.  Pretty lousy numbers when you think about gross HP as opposed to BHP that we are really concerned with.  Still, they don't mention if this rating system takes into account the very lean EPA carburetors, so I'd have to say no, which means its even worse.  If you look at the last paragraph that I highlighted in RED, this supposedly 8 hp engine I have that is run in ACTUAL conditions and NOT in optimum laboratory conditions, has a pitiful rating, as do all of our engines.

Horsepower Ratings

The power ratings shown with the individual engine series on the preceding pages are established in accordance with SAE (Society of Automotive Engineers) code J1940 (Small Engine Power & Torque Rating Procedure) (Proposed Revision 2001-09). Power curve and engine performance data are obtained in accordance with SAE J1349 (Net) or J1995 (Gross) Engine Power Test Codes.

In accordance with SAE J1349 (Net) or J1995 (Gross) Engine Power Test Codes, power curves are developed from laboratory test engines and are corrected to standard conditions which are:

If the engine will be operated under ambient conditions different from above standard conditions, the following factors should be accounted for in estimating "on site" power output:

The actual "on site" power output will also vary depending on other factors including the manner in which the engine is operated, the fuel that is used, and the application in which it is installed.

The "Maximum BHP" curve represents maximum performance output of optimum laboratory test engines of a particular model. A statistical mean of production engines, with 95% confidence, will develop no less than 85% of the Maximum BHP when tested after run-in to reduce friction and after clean-out of combustion chamber, with valves, carburetor and ignition systems adjusted to laboratory standards.

The "Recommended Maximum Operating BHP" is a calculated curve and represents 85% of the maximum BHP curve. For practical operation, BHP load and speed should be within the limits shown in the "Recommended Maximum Operating BHP" curve.

If the maximum speed of the engine specified for a given application is governed to a speed less than the speed at which the Maximum BHP occurs, the engine will not achieve the Maximum BHP in that application. For applications requiring operation at other than the recommended engine speeds, complete details of the proposed engine installation should be referred to the factory for evaluation.

Source:  Briggs & Stratton Technical/Warranty
http://www.commercialpower.com/display/router.asp?DOCID=76491

Too add to Richie's Great explanation.  There is also the question, of maybe selling the same powerplant, badged with two different HP numbers.  That could be legal if you add the disclaimer that Richie dug up from Briggs and Lawnboy. 

The test has a guideline that takes a reading (yes usually a percentage of) at the max hp produced on the HP graph..  So say thet we use a tech 9HP.  Seems the manufactured now maybe has two options,  He can put it on a machine and say it is an 8 as that is all that it will develop at the operating speed of the machine.  However from what we have been seeing, and somewhat really looking at to see if it can be disproved, is do they have the other option of Tagging the engine as a 9HP  and in the fine print, making note that your machine won't necessarily produce 9.   That along with the other aspects Richie  mentioned may all be a problem..

     If someone wants to ignor it, fine, no problem, as some of it may be false.  However ignoring it and disproving it with applying facts are two completely different aspects.

Richie tried to question it, fair amount of disbelief, however he then proved his side with facts.  You want to buy more machine, less, say the test is standard, which it is, however the results can be given to the consumer different contexts, thus allowed with hidden hard to find fine print disclaimers. That is fine and entirely your choice.In my opinion If you choose not to ignor it I think it enables you to be a better consumer.  Also a consumer who will know better ho to get a better value for their money.  Best example is the higher stated output  engine in the same category, probably has a higher mark-up from the manufacturers actual cost, It is probably not one of the machines that like home depot gets a lot of.  The manuf would supply more to the depot with the lower mark-up  and the higher mark-up to the dealer. Why cause the dealer needs more profit to survive, The manufacturer gets somewhat offset by the HD buyers not claiming as much warranty service for the miniscule problems. they fix them themselves.(the owner of the machine)  

An example of it helping you as a consumer would be to go into the dealer and saying why is it 400 dollars more for this machine.  before he speaks, you say it is not 400 for handwarners, 20 bucks cost for them, drift cutters,  20 bucks cost .  2 more inches of snow box.  maybe 75 dollars in manufacturing differential..  and I know that engine says a 9  but it is the exact same engine as the 8,  just the rating trick they seem to be allowed to use.  Sure he will maybe be stupid and loose your sell.  however he is gonna talk to the manufacturers and say I think we ought to cut this out,  or we are going to be out of business sooner or later, like your fathers oldsmobile.   (because of a negative image etc) or like lawnboy who tried to sell two lines of mowers, one a little cheaper to manufacturer.  Lawnboy still made the good high quality Supreme, however lot of consumers saying I heard lawnboys are now junk etc.  They lost a lot of market share there.  And to boot they had those problems when they did in no way disguise the lesser quality model by calling it a "utility" and stating that it had lesser features than the high end model.  Now we are talking about a marketing strategy that may be designed to give you less than what is advertized and really not adequately informing you, by disguizing it with a marketing ploy.  All that tells me is most of  the small engine manufacturers are in bed together.  kinda like a monopoly

Ben07