Last post on Sep 08, 2010 at 5:46 AM
You are in the Acura MDX
What is this discussion about?
#808 of 1262 Re: Gear Ratios [habitat1]
Nov 08, 2006 (2:22 pm)
There have been several Honda and Acura products which have also dyno'd well above the claims of the manufacturer. Even well above the old pre SAE changes.
Of course, the results will vary depending on whether you use a chassis or a hub-style dyno. I've seen the phenomenon play out with both.
As far as the MDX is concerned, Robertsmx is right about the torque curve. Something like 95% was available from below 2,500 rpms. In fact, the old spec sheets read "245 lbs-ft 3000-5000 rpm" They didn't list a single rpm point because it was flat for 2K revs.
However, as the MDX gained HP in 2003 and again in 2004 (pre SAE changes), the torque peak rose a bit to 3,500-5,000 rpms. A shift of 500 rpms isn't going to change the character of the engine radically, but, in the interest of accuracy, that's what they published.
When the SAE changes were made, the total output changed slightly, but the HP and TQ peaks did not.
So, if the engine's torque curve is so formidable, why doesn't it feel like it'll jump off the line? I've got three possible answers for that.
1. The throttle tip in is not very aggressive. Probably to save fuel during the EPA city cycle. However, if you push the go pedal all the way, tires will bark and trees will blur.
2. As mentioned above, gearing. Probably for the same reason as above.
3. DBW. Which, I suppose, is related to #1. The drive by wire system employed by Acura in all cars but the NSX seems to have a nasty bit of lag in it.
The DBW doesn't bother me ordinarily, but when I switch back to my wife's 2001 TL (mechanical pedal), I can feel it. With my normal, conservative driving style, the TL actually feels more spirited. However, if I get on MDX with a heavy foot, the 3.5L makes its torque advantage known.
Anyway, I expect the 2007 MDX will be more of the same - for best results, press the pedal with authority. I don't consider it a bad thing. When I look at how poor the fuel economy is for the BMWs, I'll accept the compromise.
#809 of 1262 Re: My Impression After My Test Drive [robertsmx]
Nov 08, 2006 (2:29 pm)
Drove an 07 MDX followed by a used 06 MDX, the 06 felt noticibly quicker off the line. Can't account for that since the specs say the curb weight is only 68 lbs more in the 07.
#810 of 1262 Re: My Impression After My Test Drive [gene00]
Nov 08, 2006 (3:53 pm)
That is what habitat1 was referring to as "buttmeter". It is the same reason why you "feel" the 06 is quicker off the line. In this instance, X5 "feels" quicker, abate the numbers.
That is what most if not all people judge a car by, "feel".
#811 of 1262 Re: Gear Ratios [robertsmx]
Nov 08, 2006 (6:49 pm)
I didn't intend to turn this into a BMW vs. Acura horsepower debate, but you are being a bit pig headed in some of your statements to make your point. Remember, I own 2 Acuras now, still claim my former S2000 as one of the best cars to ever come out of Japan and have never owned a BMW. But I'm not so insecure as to not call Acura to the carpet when they should be. Call it "tough love".
We have seen that with Honda being one of the first automakers choosing to re-rate its engine to follow new standards when it wasn’t required, even though it played against a marketing strategy.... Where was BMW?
Excuse me? Acura/Honda didn't do ANYTHING by charitable choice. Their engines had been rated overly aggressivly and, under the new standards, HAD to be downgraded. BMW used more conservative standards all along and didn't have to downgrade a single engine rating. As a matter of fact, even the Big Three only had a few engines that didn't meet their published ratings under the new standards. Spin that any way you want, but the fact is not a single other manufacturer had to make anywhere near the fleetwide horsepower revisions that Honda/Acura needed to make under the new standards. It appears to me that Acura chose the most liberal measurement method and got caught with their pants down.
As far as the MDX performance, if the gear ratios really are killing the performance to the extent you claim, shame on Acura. I am quick to criticize the idiot engineers at Chevy that take 7 liters and 400 hp / 400 ft/lbs in the lighter weight Corvette and manage to make it slower than the heavier 911S with "only" 3.8 liters and 355 hp / 295 ft-lbs. The Porsche is so precisely geared as to hit its top speed of 182 at almost exactly redline (7,200 rpm) in 6th gear. Every gear is matched to take over from the previous gear to maximize perfromance. The Corvette can't even manage 5,000 rpm in 6th and actually hits top speed in 4th and 5th. Unfortunately, from what you are saying, Acura's engineers went to the same "stupid is as stupid does" transmission gearing class. Too bad they don't offer the MDX in a 6-speed manual. They seem to know how to do those quite well.
Again, I'm not trying to turn this into a BMW vs. Acura debate. I just want Acura to do a bit better on the engineering front. They proved they could with the S2000 on the Honda side.
#812 of 1262 Re: My Impression After My Test Drive [habitat1]
Nov 08, 2006 (8:32 pm)
Couldn't have said it better myself. No TL can compare to a 550i -- period. I also agree with the sensation one gets driving the Acura (TL, RL, MDX) that you don't feel the power of a 300HP engine. The BMW engines feel just as powerful, despite their lower HP and torque specs on paper. I'm not partial to either brand, but I've driven both and the BMWs definitely feel like they take off quicker.
#813 of 1262 Re: Gear Ratios [habitat1]
Nov 08, 2006 (10:43 pm)
Interesting discuscussion. It helped me to understand this by looking at the Horsepower / Torque graph on the MDX brochure. I could not find it on the US site but you can download it from the Canadian site. Canadian Brochure, Horsepower graph is on page 10
Or below for cut and past.
#814 of 1262 Re: Gear Ratios [mdxmom]
Nov 08, 2006 (11:19 pm)
Thanks for the link! It looks like the new V6 is delivering about 225 lb-ft at 1500 rpm, and 250 lb-ft or more from 2500 rpm and continues to do so until past low 6000 rpm mark.
#815 of 1262 Re: Gear Ratios [habitat1]
Nov 08, 2006 (11:27 pm)
you are being a bit pig headed in some of your statements to make your point
It will be nice if you actually elaborated on what was pig headed about my statements.
Acura/Honda didn't do ANYTHING by charitable choice. Their engines had been rated overly aggressivly and, under the new standards, HAD to be downgraded.
Once again, it is your opinion. Nobody HAD to follow the new standard. BMW didn't. Acura/Honda did. How do you explain that? You do know that the new SAE standards were voluntary. Don't you? No its not about charity. I brought it up because you questioned "ethics".
As far as the MDX performance, if the gear ratios really are killing the performance to the extent you claim, shame on Acura.
Yes indeed. Thats something I have been saying all along, and for a while. Not just on Edmunds but on other boards too. Varmint has read my posts in another board on the same topic and related to RL/MDX that I posted couple of months ago. I knew the gearing would become a "marketing issue" since a typical test driver relies more on buttmeter than an overall understanding of how things work together, and how each component plays a role in the overall effect.
Do you think MDX's performance wouldn't be affected at all if it used 10-15% shorter gearing in the lower gears?
#816 of 1262 Re: Gear Ratios [robertsmx]
Nov 09, 2006 (1:05 am)
As far as I know, Honda/Acura wasn't the only manufacturer to re-state horsepowers on their vehicles. Toyota/Lexus also did that. The 4.3L V8 on GS was rated at 300hp (wow exactly, I wonder why?) and now it is 290hp. Just an example. Honda/Acura was quick to react to comply with the new SAE standard (which wasn't stated clearly anyway). No one's fault. Many other manufacturers decided to hold on to their numbers and comply with the new SAE standard with the new engines. For that I give credit to Honda/Acura for admitting "error" immediately. Now the new standard is more well-defined, hopefully, there is lttle room to fool around.
It is also my opinion that the problem with MDX is the gear ratio. When I first test-drove the RL (#1 on waiting list), I was disappointed after the testdrive (coming from BMW 540 V8 with ONLY 282hp). The claimed 300hp (now 290hp) was not impressive. Therefore, my decision to pass it on. Acura lost a sale of RL because of the gear ratio (now I know why). It makes the vehicle seem heavy and sluggish offline, which is bad for city driving.
Anyway, I will hold on to my Odyssey until the MDX carries a well-spreaded 6-speed tranny. And, they better start the 1st gear at 3.5+.
#817 of 1262 Re: Gear Ratios [habitat1]
Nov 09, 2006 (3:49 am)
I side with you Habitat, I road tested the 2007 MDX and a 3.6 Q7 within a day and the Q7 did feel more powerfull even though it has 20 less HP on paper. I am sure it is the torque band which does it.