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I am thinking about moving up from my 1999 Tacoma to either a 2005 or 2006 limited DC Tundra. All the reviews say that the 2006 model is completely unchanged from the 2005 model, but I notice that the 2006 is rated at about 11 less hp (282 v. 271). Does anybody know what they changed from the 2005 model or have any other suggestions about either truck?

Thanks,

Parke
 

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Lots of posts on this topic. Same motor, same power. The only thing that changed is the way they measured the power. I believe they changed to a different measurement system that is industry wide and more accurate. So I guess the 2005 measurement is a little optimistic, wheras the 2006 measurement is reality.
 

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Suggestion: Get the TRD cat backs and add 4.2% to your HP. Makes a difference....
 

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Can you please tell me what the TRD cat backs are.

Thanks

Lloyd
He was referring to the exhaust pipes sold by Toyota Racing Development
(TRD) that replaces your stock pipe and muffler from the catalytic converter
back (cat back). The system is constructed of stainless steel, is worth around
10 hp, livens up the sound a bit and is available with single or dual outlets. It
also does not affect your Toyota warranty.

dogger
 

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For 2005, Toyota used SAE Net horsepower ratings. The problem with SAE Net ratings is that it was established in the early 70s before computer-controlled engines were around. So there are either no rules or relaxed rules on things like ignition timing, fuel mapping, intake/exhaust tracts, etc. So a car manufacturer could take an engine, advance the timing and change the fuel delivery (as well as run a higher octane than they recommend for the vehicle), and tweak some higher numbers out of it.

Around 2005/06, the SAE developed the SAE Certified power rating system. Basically what it means is that the engine has to be tested in the EXACT configuration it will be sold in- everything from the paper air filter to the recommended fuel octane. On top of this, the tests have to be verified by a neutral 3rd party. It isn't a required method for measuring power (yet), it is strictly voluntary. Yet a lot of the manufacturers have adopted it. You'll notice in magazines like Car and Driver and Motor Trend that they will make a note next to a car's power rating if it is SAE Certified.

Toyota decided to use the SAE Certified ratings on the 06 Tundra, which is why there is an 11 HP "loss" with that model. In reality, this means that Toyota fudged the numbers a bit in testing with the 2005 model. Quite a few Hondas and also some Toyotas "lost" HP in 2006 due to using the SAE Certified methods. The Honda Civic Si dropped from 201 HP to something like 197. One of the more famous cases of power output changing was with the 2006 Corvette Z06. Before it came out, it was rated at 500 HP SAE Net. Oddly enough, switching to the SAE Certified standards bumped that up to 505.

What is interesting though, is that the 07 Tundra is back to the SAE Net ratings system, which raises some questions for me, especially with the torque rating just over 400 lb-ft. I'd be willing to bet that if they used the SAE Certified standard, it would be slightly under 400 lb-ft, something like 397 or something. But you know, 401 just has a much nicer ring to it. (If you're wondering where I got the information that the 07 is not SAE Certified, it is in the April 2007 Motor Trend, page 98. The Chevy Silverado is noted to use SAE Certified standards, and the Tundra is not.)

In a nutshell- the 2005 Tundra really makes 271 HP, just like the 06. Hope this helps.
 

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The TRD cat back duals do not improve quarter mile times on the 2006. They do offer excellent fit and finish, and ease of installation, however.
 

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I am thinking about moving up from my 1999 Tacoma to either a 2005 or 2006 limited DC Tundra. All the reviews say that the 2006 model is completely unchanged from the 2005 model, but I notice that the 2006 is rated at about 11 less hp (282 v. 271). Does anybody know what they changed from the 2005 model or have any other suggestions about either truck?

Thanks,

Parke
As stated before, this is net flywheel hp. The difference between 05 and 06 is due to the test being conducted with all engine driven accessories in place and operating with the recommended grade fuel. 05 power rating was measured without all accessories driven and with an undisclosed fuel grade - this is the only difference.
 

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I asked about that very thing, and I was told that they used a different measuring system. But, is actually the same. I asked my dealer about that. The guy I talked to seemed very knowledgeable.
 
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