swajames

Those Nissans were from an era where a number of Japanese manufacturers agreed to limit their cars at 276bhp, but most of them put out cars that made more. Those 400 bhp Skylines weren't officially sold here, though...

pjinca

Also true, but still another example of a TT V6 that kicks the crap out of our TT I6

cmoore_

Dyno readings unreliable? LOL, please explain. Manufacturers underrating horsepower is nothing new. Why havnt we heard any lawsuits over the decades about owners suing manufacturers regarding rated horsepower, wreck or not? Its my understanding that the 535i dynos approx 280whp (reliably on multiple dynos) therefore the advertised 300 hp is not accurate. It is more like 330-340hp. This is proven info. Given all the 535i's that have been in fender benders, how come we havnt heard any lawsuits over "more than advertised hp" lol. This argument is bs.



FYI, muscle cars in the 60's were rated much different than today. They were rated on an engine dyno with no accessories vs todays standard in which they are engine dynoed with accessories and rated at the flywheel. So a 400hp v8 in the 60's really only made approx 330hp in todays numbers.



Back to topic though. We will continue to see more and more lower displacement engines with forced induction across the board with all manufacturers simply because of upcoming mpg requirements. No other explanation IMO. From an enthusiast perspective this isnt necessarily a bad thing. Forced induction from the factory is your average gear heads dream

But I still love my NA 545i

pjinca

I understand that muscle cars were rated differently, my example was simply showing US car makers are known for this practice as well.

The point of this thread IMHO, should not be about merely displacement. It should be questioning why BMW is falling behind other manufacturers in terms of power and torque, but not getting significantly more fuel economy. Give me one or the other at least (preferably HP ).
Especially when you see current models from many other makers matching - easily - the MPG numbers, bit far exceeding the power numbers of our I6. Even BMW V8's are under powered when compared to the competitors.

Excession

cmoore partially addressed this but the facts seem to show there should be an inclination to underreport horespower figures to avoid lawsuits such as:

http://consumeraffairs.com/news03/mazda_buyback.html

&

http://www.consumeraffairs.com/news0...ettlement.html

swajames

In the case you posted, the RX-8 consistently produced less power than was advertised... That's why there was an issue. As I said, manufacturing tolerances today are tighter than ever before and cars will generally produce close to their rated output. A tolerance of a couple of percent, either way, would be within the bounds of reasonability, a difference of around 20% is a different story.

swajames

Absolutely - dyno readings are all over the map... Different dynos, such as Mustang or DynoJet, will give you very different results for the same car, and the procedure followed by the operator can massively influence the results. It's far from an exact science. Look at the many dyno reports from after market manufacturers claiming gains, and the often contrary reports from customers or competitors, again supported be dyno-delivered evidence, claiming the gains are lesser or are non-existant. Simply put, there are many variables that can significantly influence the outcome and, ultimately, dyno readings are little more than fodder for the uncritical or easily persuaded. Either way, my point remains - selling a car with so significant a delta between advertised and actual HP would indeed be asking for trouble. It would indeed make a reasonable defense argument that an incident was not your fault because you were unknowingly driving a vehicle that was much more powerful than you believed it was. As another member posted, manufacturers like Mazda were sued for delivering less than the rated HP, it's far from a stretch to see why the converse could create an exposure. Ultimately, my own judgement is that those examples you provide are simply an example of Endowment Theory in operation and some owners wanting to attach greater value to the car they own by believing they got more than they paid for - back to those mythical "German horses" again.

JohnC

Why worry about advertised HP when most BMW's outperform cars with more HP. A 328i will run right with a 280hp Acura TSX V6. I was pulling out onto a highway today with my own merging lane and there was a guy in front of me in a new Maxima. He was flooring it around every turn and down every stretch when I was behind him so I know he floored it pulling onto the highway. I stayed right behind him with my 215HP to his 270?. I know off the line would be a different story, but when the I6 gets into it's RPM range, it is silky and powerful for it's size. I had a V6 Audi and the I6 sounds so much better.
I think BMW can easily squeeze 275 HP out of the 3.0, but the turbo game is new to them and they are taking small steps for reliability and efficiency. Look how fast they came out with the 335is with more HP and a lot more torque. I think that the high power N/A days are over and we will have some high HP turbo cars to look forward to. I hope they never go V6. The I6 is a far better setup. Remember the Supra? Also GM made a 4.2 for their Trailblazer that was probably there best engine ever. It was due to cost and practical uses of it that they stopped it. Also, BMW can go a little larger in displacement without having to use a longer block. They did a 3.2 before. I think it more about being bullet proof.

kajin99

especially if you include aircraft engines...

pukka

What about weight balance? Correct me if I'm wrong but BMW's are pretty close to the 50/50 ratio which helps in handling and stability no?? It would also be the reason why the the M3 switched to a V8, they just couldn't fit a bigger I6 in there and still keep the desired balance.

An inline motor is also less prone to vibration.