Acura RDX

stever

Thanks for the reminder - here's the place:

Acura RDX - Real World MPG

c_hunter

With auto trans and the characteristics of the engine, I think the RDX drivetrain builds up to peak acceleration rather gradually, and wouldn't expect a need to smother the engine performance off the line (in fact, that would be an embarrasing kludge in my opinion). If done right, the AWD system should be working in concert with the engine, and should be able to react fast enough to handle heavy-handed throttle applications. I can only use Subaru for real world experience, but they have it down to an art -- fore/aft power shifting is even used to offset the effects of dive and squat under heavy decelleration and acceleration, respectively. Since the Acura's SH-AWD is quite sophisticated, I would expect similar "smarts" from the RDX even though it has a heavy FWD bias. If you're going to the trouble to have a good AWD system, it should be capable of managing the drivetrain and allowing you to effectively put down as much power as possible -- to me, that's one of the main points of AWD (which Subaru has marketed for years). Unfortunately, most shoppers associate AWD with wet-weather capability and may not appreciate its dry-weather importance. A car like the STi can put down 300HP without drama because of a good AWD system. In a FWD car, that would be inconceivable without some eletronic nanny controls or accepting lousy behavior and poor handling/stability (and in cases like the Acura TL, some of both).

robertsmx

In a FWD car, that would be inconceivable without some eletronic nanny controls or accepting lousy behavior and poor handling/stability (and in cases like the Acura TL, some of both).

Not sure what you're talking about there especially as it pertains to TL which doesn't have "poor handling/stability". What you hear about isn't really "torque steer" (and only noticeable in 6MT models and around corners... better way is to turn the VSA off, contrary to expecting it to help actually).

But, RDX is far from being a FWD vehicle. In fact, its AWD cruising split is similar to Subaru's with automatic transmission (90-10). During heavy acceleration in a straightline, 45% of the torque is directed to the rear axle (upto 70% when going around a corner).

That said, turbo lag in RDX is being overblown. If it is bad in RDX, imagine how worse it is in CX-7 that Motor Trend brought up in its latest comparison.

gnahce

I had a chance to testdrive the RDX on Saturday and a question for others on this forum on the topic of turbolag. When I gunned the engine from a stop, I definitely heard the turbo turn on a few seconds after the gas was pressed down. So the sound of the car gave me the impression that the car hesitated when accelerating. However if I focused more on the feeling of acceleration rather than the noise (which my wife compared to that of a jet engine taking off) the car acceleration was actually quite responsive and smooth.

Any thoughts?

Personally I liked the car when I saw the pictures and specs, but the noise of the turbo was a real turn-off.

robertsmx

Apparently (based on interview of the chief designer), the turbo whoosh entering the cabin is by design, to provide a sporting character to the RDX driving experience.

Some will like it, many may not.

c_hunter

Actually, my Subaru, and any of the models with VTD AWD and the 5-spd auto transmission (5EAT), have a 45% front / 55% rear nominal bias. It can vary fore/aft from that as needed, but the default gives it a nice sporting neutral/RWD bias.

Some of the other Subarus with the 4EAT are 90F/10R nominal, and they have a very FWD tendency with handling. I got a similar feeling from the RDX with some initial understeer, and Car & Driver noted this as well (though working the SH-AWD the right way can apparently minimize this). In addition, the RDX is based on a FWD transverse engine platform, so it really has a FWD behavior wired in at a basic level.

The TL (especially 6MT) is widely acknowledged by the car mags as being overpowered for FWD, and I have to agree with this assesment -- it just did not have good dynamics under power when I test drove one a couple years ago. Now keep in mind my daily driver is a Honda S2000, so perhaps I am spoiled by that car's excellent RWD handling characteristics, but I felt like the TL was nose heavy and quite clumsy under full throttle. I just don't have a high opinion of FWD for sports cars, going back to my 97 Honda Prelude SH. It was a great car, but not even in the league of good RWD sports cars like the S2K or Vette.

c_hunter

I kind of like the turbo whoosh, and it's quite restrained in the RDX. If that's your only turn off, don't worry about it -- I think that's a fairly minor concern and you'll get used to it in no time.

ateixeira

Robert: craig's turbo model uses VTD AWD, and that model defaults to a 45/55 power split, so it's actually rear biased.

Subaru does still use a 90/10 split on cheaper models, the base 2.5i for instance.

-juice

smaslin

Only gone through two tanks of gas but so far I'm getting 19.6 mpg. On both tanks I compared the mpg from the computer to that computed at the pump; both where very close. Best mileage to date was 21.5 mpg during an 80 mile highway loop from MD to VA at 70 mph.

robertsmx

The TL (especially 6MT) is widely acknowledged by the car mags as being overpowered for FWD

This continues to be kinda OT, but I will address it one more time. TL's issue isn't (or I should say, wasn't) torque steer as those magazines concluded. It was "self steer", a logic in the VSA that "argued" against driver's will. This has apparently been fixed by revising that logic since 2006 model (perhaps a reason I didn't experience it in my test drive). Based on preliminary input, that often misreported issue doesn't exist in the 286 HP 2007 TL-S either.

So, it is not that electronic gadgetry always helps against bad behavior, sometimes it creates it (most are tuned to be safer by way of inducing understeer as opposed to oversteer). And as wwest pointed out, ECU is indeed (often) used to manage power distribution, more true with DBW set ups. Some of that reported lag in RDX may be a result of DBW interference which might be limiting power to the wheels during aggressive throttling from stand still.

c_hunter

Some of that reported lag in RDX may be a result of DBW interference which might be limiting power to the wheels during aggressive throttling from stand still.

When it happens under normal driving conditions nowhere near the limit of wheelspin, it's hard to imagine it's an intentional throttle mapping. There's no reason to purposely make the vehicle appear sluggish in normal driving. Perhaps at the limit of adhesion, yes (and that limit is damn high with AWD -- to the point where traction control practices are rare), but not under normal throttle inputs, no way.

Actually, one way to settle the debate is to power-brake the vehicle off the line, if anybody wants to give that a try. Getting the RPMs up to the point where the torque converter stalls ought to get the turbo boosting fairly well. At that point actual turbo lag ought to be nil. Everything from that point would be VSA and AWD. I am guessing the RDX would dig in and rocket off the line...

wwest

Now that electric power stearing is becoming inexpensive enough to be feasible across model lines more FWD manufacturers are not only using it to overcome torque stear "feedback" to the stearing wheel, but also as a sort of "stick-shaker" simulation to advise the driver that it is advisable to increase/decrease the stearing the angle in the current direction....

Toyota and Lexus VSC systems w/electric PS actually reduce the power assist level if VSC detects that overstear or understearing will/might be exacerbated if the driver insists on turning the stearing wheel in the "wrong" direction.

Now if we could just have them replace the Accelerator pedal return spring with a torque motor so pedal resistance could be increased and vibrate the pedal slightly during dethrottling events...

And maybe disable ABS unless VSC indicates the need.

robertsmx

DBW is already designed to do some of that. From Acura literature:

"It (drive by wire) takes information from various sensors in the engine and around the chassis, processes the data in its ECU, and then opens the throttle according to conditions. So, if smooth driving is desirable, such as when the road is slippery or traffic congested, throttle response is more gradual..."

Jumping on gas pedal from a complete stop may be forcing DBW to "adjust". So the noticeable lag may not be completely from the turbo, but potentially also from DBW. This was the point I thought you were trying to make.

varmint

Sorry. Coming back from a week-long vacation, so I'm catching up on old posts.

"Well, they disconnected the rear driveshaft because they were on a 2-wheel dyno, so they didn't get realistic data. They really should have taken a litle extra time to locate a 4-wheel dyno (they are commonly used in the Subaru/Mitsu tuner scene)."

Most AWD dynos are not going to give you data that is any more "realistic". Jeff (one of the TOV guys) explains this in response to a post similar to yours. Except for the very latest AWD Dynojet, AWD dynos measure output with the front and rear decoulped. With Acura's AWD system, the ECU would equate this with an infinite slip situation - as if the vehicle had no connection with the ground. Which is not at all realistic and would result in more losses than you'd see on terra firma.

Given that their goal was to evaluate the engine, regardless of AWD losses, I think their approach was fine.

If they wanted to get "realistic numbers" even an ordinary AWD dyno would be insufficient.

varmint

"varmint - did you switch VSA off? I think you waited so long for a test drive that you just got a bit too excited."

No, as a matter of fact, I could feel the VSA kick in when things got freaky and the nose started getting out of shape.

With SH-AWD, the way to drive the car is slow in/fast out. Enter the curve at a more modest speed, then hammer it when you reach the apex. The AWD will route power back and outside and the vehicle will whip right around the corner. You'll exit the turn at maximum speed.

That's the theory. I knew it going into the test drive, but wanted to find out just how true it was. So, I pushed the envelope to see what would happen.

varmint

"Having to tumble the base of the rear seats before folding the seat backs is a hassle. I have had previous vehicles that were like this, and you lose valuable storage space in the rear seat footwells (good places for ski boots, hiking boots, small cooler, laptop case, etc). I never realized how much of a pain this was until my 05 Outback came with rear seatbacks that fold flat in a single step, with the seat base in place. It's a pity Acura couldn't do this on the RDX -- there is no reason not to."

Ditto that for me. My 1999 CR-V allowed me to stash objects in the footwell of the second row. Ski boots was a common item on my list, too.

The one thing I will say is that the design in the RDX does allow the seatback to fold almost perfectly flat. I compared the seats of the X3 and CX-7 and neither of them fold as flat. And, in the case of the CX-7, the seats are low to the floor as a result of trying to achieve the same "flatness".

wwest

Yes, you're correct, absolutely!

But what I was suggesting is that a torque motor be used in place of the accelerator pedal return spring so the driver could be provided feedback when the DBW system is not following the pedal.

For instance the torque motor could increase pedal depression resistance if dethrottling is active, the more dethrottling the more pedal depression resistance. Additionally the pedal could be caused to "vibrate" (just as does the ABS when active) when DBW is "intefering" with the driver's "wishes".

wwest

I'm not sure I understand your statement about an AWD/4WD dyno testing.

Back when I wanted to prove to a few adversaries that the Lexus RX300 AWD (2001) was really only FWD I paid to have the RX tested on a 4 wheel dyno.

We had to disable the traction control system but that was as simple as pulling the ABS pumpmotor fuse.

We initially ran the test with the dyno uncoupled front/rear but used the dyno braking system to present the RX's front drive and rear drive with equal "rolling" resistance at 40 MPH.

Then by adding more dyno braking resistance at the rear the VC began to come online and diverted ~20% of the engine torque to the rear.

It was all very confusing initially to the test techician because no amount of dyno braking at the rear would "load" up the engine. It takes several minutes for the VC to heat up enough to begin coupling a "reasonable" level (by Toyota and Lexus "measure")of engine torque to the rear wheels.

Net result is that the RX300 and likely the RX350 (the RX330 has no VC)are mostly FWD, 95/5, and cannot allocate engine torque to the rear except under extreme long term front wheelslip/spin circumstances.

Personally I see no problem in testing the RDX on a 4 wheel dyno.

carlitos92

Actually, one way to settle the debate is to power-brake the vehicle off the line, if anybody wants to give that a try.

YES!!! So... who's going back to the dealer with me for another test drive this weekend?

lahiri

RDX is a bomb-making chemical and one of Al Qaeda's favorites. Acura needs to find a different name for the SUV.

wwest

Yes, and if Bush has his way then we'll all be showing up at the airport wearing nothing but a speedo swim suit, or even less.

Time to move on...

bodble2

"...my 97 Honda Prelude SH. It was a great car, but not even in the league of good RWD sports cars like the S2K or Vette."

Shocking!! One would have thought it should have been able to walk all over those 2 econoboxes!

Seriously, I owned a 2000 SH briefly. I thought that generation of the Prelude ('97 - 2001) was one of the most over-rated and over-hyped cars. It was a nice car, a very good car even. But based on how the car mags raved and drooled over it, I thought I was buying a bargain Boxster. But in reality, the power was unremarkable until you hit 5K on the tach, the vaunted 5-speed manual was notchy and badly needed a 6th gear, the effectiveness of the ATTS questionable and the equipment list rather underwhelming for the price.

varmint

If what you are trying to accomplish is testing the power routing capabilities of an AWD system, yes, an AWD dyno would be required. However, does braking the dyno drum sound like a good way to measure engine output?

The boys at TOV were interested in getting a rough idea of how much power the *engine* cranks out.

Decoupling the rear prop shaft obviously creates a situation where the numbers on the dyno are not going to match "real world" power output. But it does isolate the engine as much as possible.

Had they put the RDX on a typical AWD dyno, they would have introduced other variables. This in large part because all but the latest AWD dynojet leave the front and rear freewheeling. With SH-AWD, the system would freak out not knowing which of two or three directions to send power. The end result is a test which still would not accurately reflect "real world" power output. Nor would it give an accurate picture of what the engine can do.

Keep in mind, the TOV crew conduct the dyno test and under car analysis with an eye on the tuner market. Shawn Church (the guy in the vid) owns and operates a shop in SoCal. They are picking the vehicle apart, looking for ways to improve performance. Their goal with this dyno test was to see how much power is being "generated" since the engine of a vehicle is the most common component to get modded.

robertsmx

RDX is not an Al Qaeda patent. It is also the name of an explosive chemical used by militaries around the world, as well as by industries. Next you're going to say that Al Qaeda uses Toyota, Ford, GM, Dodge, Nissan... vehicles so you're not going to buy those brands. Get over it, look at the vehicle for what it is. Don't politicize it.

c_hunter

Keep in mind, the TOV crew conduct the dyno test and under car analysis with an eye on the tuner market. Shawn Church (the guy in the vid) owns and operates a shop in SoCal. They are picking the vehicle apart, looking for ways to improve performance. Their goal with this dyno test was to see how much power is being "generated" since the engine of a vehicle is the most common component to get modded.

Yeah, but he was clueless about most of the parts under the car so you have to wonder about his credentials. His discussion of aerodynamic effects made me cringe and the fact that they took part of the exhaust off a turbo motor and were surprised by the results says it all -- they clearly have no concept of backpressure or how turbos operate. I never had a problem with TOV until I saw those videos. These guys are probably not engineers, and I wouldn't put a whole lot of faith in what they say.

bosi77

How much water can a RDX safely go through?

varmint

You can head over there and take that up with them.

varmint

Not to put too fine a point on it, but... If you're asking that question, you're shopping up the wrong tree.

The RDX appears to make zero concessions to the off-roading sport enthusiasts. It is purely a road-going vehicle.

wwest

"....However, does braking the dyno drum sound like a good way to measure engine output?..."

Is there another way.....?

First, the 4 wheel dyno that was used to test my RX300 could have the front and rear "drum" mechanically, solidly, coupled so there would have been no issue of F/R torque apportioning. We actually tested in that way first to determine overall HP/torque.

Uncoupling and then braking the rear drum only makes it appear as if the front is slipping and thereby torque percentage apportioned to the rear can be determined. Vice versa for the front.

lahiri

Why not call it something else, e.g. RAX? Al Qaeda isn't a political party and there's nothing political about what I said. Also, why not bring back names like Vigor, Legend? I can't believe that a company that makes nice cars is unable to find out nice names.

varmint

RAX is a skateboard supplier. You want to name a luxury perfomance vehicle after a skateboard? :P

robertsmx

Like I said before RDX is not an Al Qaeda patent. It is a chemical that has been widely used for decades by the military and in commercial applications.

Are you going to stop using cell phones if you learnt they were being used as detonation devices? I hope not. That said, I'm curious to see what the RDX (as in the Acura) actually stands for. MDX we know arrived from "Multi-dimensional" vehicle.

stever

One RD-X concept was a hybrid that boasted twin electric motors to power the rear wheels for extra traction - so, my guess is that RDX stands for "Rear Drive - eXtra." No? Ok, how about Really Decent eXample?

Somewhere along the way Acura lost the extra motors and the dash in the name. And the rosewood covered floor.

robertsmx

Rowdy Dowdy Xtraordinaire

c_hunter

Nowadays, everybody is using "X" to label their "crossover" vehicles....

robertsmx

AFAIK, for Acura, "X" started as a designation for prototypes/concepts, with 1995 CL-X. 1998 TL-X followed it up. MDX was the first Acura to keep "X" to production form.

However, NSX has had it since its launch in 1989. But there the "X" implied "eXperimental" (Neo Sport eXperimental). Perhaps that "X" was also for prototype only but carried onto production name.

varmint

MDX stood for "Multi Dimensional Cross-over". Yeah, I know that X and crossover doesn't match up, but we can't expect marketing folks to spell correctly and promote cars, can we?

nyccarguy

Don't get me wrong, I love my '01 Type SH Prelude (72,000 miles). If I knew then what I know now (20/20 hindsight) I would have stuck with the base model. I agree that the ATTS effectiveness is questionable. It cost $2500 more than a base Prelude and cost me an extra $800 when I had my clutch replaced at 52,000 miles. The ATTS unit has to be removed and re-installed in order for the clutch to be replaced (amounting in an extra 5 hours of labor :mad: )

c_hunter

Yikes, that's a downside to ATTS I guess! One benefit the SH model got was a much better suspension than the base models. I am not sure if it was worth $2500 however (the spoiler was only worth $400-500 on the street).

So why did you need a clutch at 52K? I had 70K miles on my 97 SH when I traded it in, and the clutch was doing great.

nyccarguy

My Prelude basically spent a little more than the first two years of its life in NYC. I lived in Manhattan (parked on the street) and commuted to my job in The Bronx. My ride to work was great as there aren't too many people on the road before 7:00 AM going out of the city. Coming home the traffic was atrocious, bumper to bumper, on and off the clutch between 1st & 2nd gear (3rd once in a while)...Then once I got off the exit it was time to drive around looking for a parking space on the street, stopping at every light (they aren't in sync going across town, and finally it always took a little bit extra getting my car into the spot with its abnormally wide turning radius (and my anal retentivness when it comes to parallel parking).

I never noticed a problem or if the clutch was "slipping." One day driving I went to merge onto the highway. 1st to second was no problem, then the car wouldn't go into third unless I double clutched. I brought it to the dealer and he said the clutch was fried. He said the traffic killed it.

I didn't replace it with another stock Honda clutch. I actually replaced it with a Centerforce Clutch which is much stronger than the stock Honda clutch.

ateixeira

RDX is a bomb-making chemical and one of Al Qaeda's favorites. Acura needs to find a different name for the SUV.

Why stop there?

And we should boycott the Forester because the Unabomber hid in the Forest.

Ford should rename the Escape because we don't want to encourage escaped convicts!

I won't mention what LaCrosse means in Canada.

Avalanche - people die in those. Boycott Chevy.

Chrysler Crossfire! Need I say more?

Dodge Caliber? Oh no, more weapons!

Vipers bite people.

Tiburons do as well.

And all Jaguars.

Titans did something bad, I just don't remember what it was. Boycott Nissan.

Boxster sounds too much like Boxer, more violence. Shame on Porsche.

Touarge is too tribal. Cherokee and Sequoia too.

Do you realize how silly that all sounds?

-juice

ateixeira

X is pronounced "cross", as it would be in X-Walk or Rail Road X-ing.

In Subaru lingo XS means Crossover Sports.

-juice

rdxsteve

That's the funniest post in a long time! Thank you and touché.

teledatageek

Have to say I was impressed all the way around. I thought the power curve was pretty nice, a bit better than my FX35. Seemed quicker to me than the FX but I don't think that really is the case based on numbers. The navigation system was great with the voice commands (much better than our '03, MDX). Felt a little bumpy/stiff but not unlike my FX35. Stereo system was fabulous.

So, I'm interested enough to explore the possibility of trading in the FX35 (2005). Dealer said they have already sold and delivered nine and are trying to get more for buyers. Typically selling at MSRP, but have done slight deals for mucho repeat customers. Of course they reference Kelly Blue Book as the trade in value bible. My brief look suggested that they lop off 10%. So, the initial offer would likely be my FX35 with Tech Pkg (23K miles) + $10K

So, my questions to anyone who would like to help.... Does the deal outlined seem fair? (Given NY has 8% sales tax, that has to be factored in on a trade vs. outright sale as that could likely cut in half the advantage of private sale). Not that I think anyone has driven the RDX in snow yet, any thoughts on if the Acura SH-AWD system would be better than the FX35's? I haven't been very impressed with the snow handling of the FX and haven't really had a rough winter to push it either. I don't think dry condition handling would be that much better than the FX. Of course my big issue as always been the crappy Infiniti NAV system and while I've thought of getting an aftermarket one, it's not the way I want to go. It would also be nice to get integrated bluetooth.

Other than obviously it costs money... any other pro/con's in making a move like this?

Thanks in advance!

kamdog

My daughter's boyfriend sells Acuras, and he says they aren't moving. People comment about the poor gas milage, and the fact that they can get an MDX for the same price. Just wanted this out there. He says they will have to start discounting soon.

c_hunter

That's interesting -- thanks for the info. My local dealer made a big deal about demand being strong, but they have the same 3 RDX's on the lot that were there a few weeks ago, and more have arrived. They are all tech-models, so that could be part of it. I already have a hard time accepting the $33,665 price for the base model, and can't even comprehend $37K for the tech. I think both trim levels would be more reasonable with a $2K to $3K drop in price. Gas mileage is one of my key concerns about this vehicle.

bbydad

Hey- that's interesting -- i didn't know that you could save sales tax through trade-in as opposed to two separate sales. Is that true for every state? (I'm in MA). I had originally planned to sell my car privately, but will have to think about trade-ins. I just have a feeling they are not going to give me Kelly blue book or anything close without having to shop it around to a bunch of dealers.

Agree with the other posts -- i've heard RDX is selling way below expectations. Judging by the frequency of the calls I keep getting from the same dealers pitching the same cars, I'd have to say that prices are due to fall very soon.

teledatageek

I would think that the way a trade in works at a dealer is the same in each state. Essentially, the trade value comes off the price and you pay sales tax on the bottom line price. With a private sale, you are buying the car at your negotiated price and paying sales tax on the total amount.

In a high tax state like NY, that 8% can add up quickly. So, I always weigh the hassle factor in selling on your own. Listing, test drives, phone calls, timing, etc. vs. driving the car to the dealer and driving away in your new one. Of course it doesn't hurt to give it a quick try on eBay or something, you never know.

Sounds like from these posts, the dealers may be willing to deal more in a few months. I can wait, no hurries.... although it would be nice to do something before winter.

bbydad

Yes, i agree the hassle factor of selling on your own is a put-off. Plus, you got to register and insure two cars for a while until you can sell off the old one. I think I might shop it around to dealers to get a sense of the range in prices. I am also going to wait until dealers are more flexible with pricing, but like you I'd prefer to have the SH-AWD in time for the NE winters.

kyfdx

It definitely varies by state..

In Kentucky, the only time a credit is given, is if you trade one used car for another used car.. No credit at all on new car purchases..

Some states give no credit, period..