The other day I was at a BBQ with some friends and someone asked me how I liked driving a 4cyl. So I started by saying that the car was great and that it had plenty of power and I personally thought that the use of a V6 in this car would of had no extra benefit over the 4. Then I got the one statment that DRIVES ME CRAZY!!! "Well theres no replacement for displacement!!" I gotta say that having driven many v8 trucks including a 2008 escalade which is supposed to be the best engine ever according to those that drive them....I was less than impressed. 400hp pushing around 6000lbs doesn't make for a performance vehicle.

For those that are more informed there is a replacement for displacement and thats weight savings!!!! The next time I hear some moron who drives an f150 v8 tell me about how fast his truck is I'm going to gag. I feel like after the cars from the 60's all people think regardless of power a v8 or v6 means fast!!!

OK so now to my question for anyone who has had the RDX for a little while. Do you think the engine is the best fit for the vehicle? and if not what would you suggest for future design. I personally think this engine was a great move by Acura to get into the low displacement turbo charged engines.

In terms of performance this CUV crushes the competition. Look at all the V6's out there Outlander, Tribeca, Audi Q7 there all dogs!! Even with BMW upping the ante with more power from its V6 it still gets edged out.

 

I agree with you completly Ineedatruck, I feel that this engine is a great one probably one of hondas best engines to date. The Turbo 4 gives the RDX more personality than most suv/cuv and cars out there. they might have got better MPG with a n/a 6 cyl. but they wouldn't be able to produce the torque they do with the turbo. to wrap it up the turbo charged engine was the deciding factor in my purchase of the RDX i couldn't be more pleased with it...

 

The big problem for me is the lack of instant torque.

My new route to work takes me thru Mulholland Hwy and over the Santa Monica mountains, and up Pacific Coast Hwy twice a day. Unless you are in manual mode and spinning the motor over 4500 RPM, there is no instant torque to get the weight transfer when exiting a corner. You really have to plan corners to dial in the turbo lag so you are on boost just after the apex......and it's a little tiring. It's not very sporting and in this instance, the BMW 3.0 straight six cylinder is just about the ultimate application. That being said - I clarify that the SH-AWD helps a great deal because it helps to shift what little torque you have on tap around.

Also: FWIW with 11,000 miles my new average MPG is now 16.9 because the boost is on all the time to get over the hill and back, iand t sucks the fuel - but my new route is shorter than the old one so the overall cost to me is lower. For clarification: I'd rather be complaining about gas mileage than getting smoked by a Del Sol.

The other side of the coin, is that the current driveline is great for everyday streetfighting. I love it when people attempt a "gutter jump". Overall the car is still a little juvenile for me, but since I got NO hits when trying to sell it, I'm resigned to keeping it and giving it to Mrs. Rizzo when her Benz lease is up in May (she thinks it's "cute"), and I like it more now than when i first bought it.

 

Me too. Don't get me wrong. I love my RDX, but too many times it's not ready to jump when I am (like pulling out into traffic, coming out of turns, etc.). Once it's ready, it goes like a rocket - but the 'once it's ready' part is the problem. The turbo lag is annoying, and for some reason, it feels worse than my last turbo (1988). It might just be the turbo lag combined with throttle lag getting to me...doesn't this thing have 'throttle by wire'?

Mike

 

I had the RDX for an all day loaner. I really liked it, but I have not experienced this much turbo lag since I drove a 1983 MB 300SD turbodeisel. I actually thought I broke my neighbors Benz when I had the pedal to the floor and the car was not moving. Once the boost kicked in, it was a blast to drive. Same feeling with the RDX.

 

I think it is more throttle lag. Trust me, a 2.0 WRX has way way way way way way more lag than an RDX.

Doesn't really bother me. My stoplight races are behind me and it is not noticeable on the highway.

 

I notice lag be it turbo or throttle much more when it is very hot outside and the a/c is running. If it is an issue like pulling out into traffic and I need that power I turn off the a/c until the move is accomplished. I could be wrong but I think a lot of those who notice this are in warmer climates and would be using the a/c much more than we would up here.

I am not experienced with any other turbo's so I can only go by what I hear and read and it seems most car magazines and driving show's seem to think it is minimable lag compared to most.

As far as the curves and corners are concerned I have no problem down shifting to maintain the torque and power that I feel is necessary to enter and exit. If I was driving a stick it would require the same thing so no big deal to me as I feel the paddle shifters work quite well in most circumstances.

 

I just can't get used to those silly paddle shifters. They just make driving difficult for me. I can't shift without a clutch. I still say this thing needs a real manual, but I know it will never happen.

Oh...and right or wrong, my dealer told me yesterday that it's looking like the TSX is going to be released at some point with the RDX drivetrain. With a stick, that would probably be a blast to drive....

Mike

 

Another $0.02: The STI motor is a better motor than pretty much every NA V6 ever produced. It makes 290 ftlbs at 4400 rpm. It has more low end torque than the Nissan 3.5L in the Z. It has gobs more modificaton potential. The new 3.7L will probably just match it in terms of low-end.

If Suabru ever gets off their asses and puts DI and some sort of variable flow turbo or twin scroll on, it will be a monster, even more low end torque. DI does way more for a turbo engine because of the charge cooling effect.

I think the tech curve on NA engines is pretty much played. Honda and Nissan are both going bigger (35. to 3.7L) to make more power and torque.

 

Brizey I dont want to get off the RDX but I must agree with you about the motor in the STI. Fellow gearhead friend of mine asked me to help him over the summer really start testing the limits of that motor. From what I've seen so far the power its able to handle is amazing. I believe that as of the last dyno run we did it was putting about 600 hp down. I'm sure there are plenty of guys running more power than that from that motor but we really just increased the size of the turbo and a couple of other "tweaks".

With the awd system in that car I cant wait to see what all that power does at the track. We need to get to a strip one of these weekends and get some times. I'm guessing with the low weight hes probably going to be solidly into the 10's my best guess is between 10.50 and 10.80

Should be good enough to shock a few people.

 

Have to agree that the RDX turbo is a very well worked out engine from Honda. A really smooth inline 4, comparable to some V6's. I also do notice the turbo lag, but only for a brief duration... The torque delivery is excellent, making passing long trucks on the freeway a breeze...
I drove the WRX turbo once, and the turbo lag is definitely more noticeable...nothing happens until you reach about 3500-4000 rpm... weird... you would expect turbos to come in a little sooner than that...
The only other large displacement engine that would be of worth to talk about would be the inline sixes from BMW, those powerplants simply are the smoothest and delivers power ever so linearly, the torque never lets up... starts up with 80% of max torque at 1800 rpm... pure exhilaration...

 

That's why I said "V"6's. Inline sixes always seem to make better low end. The old NA Supra motor was a very un-hyped but nice motor (I THINK it is essentially what was in the IS300). By the IS300 era, it was underpowered, but in 1994, 220 HP out of a 3.0L NA motor was killer. It made 210 ftlbs at 4800 RPM. It was overshadowed by the turbo and NSX motor, but it was better than the non-M BMW motors of that era. It made more low end torque than the NSX.

 

Wow brizey i did not know that about the Supra n/a engine great fun fact. but it is easy to see why it was over shadowed by the twin turbo the supra was just to heavy for 220 hp.

 

I also think that the RDX motor is underrated. The hp/torque/weight/0-60/quarter-mile data just doesn't add up.

Also, compare it to the MDX. The MDX weighs about 15% more, has almost the same gearing, makes 25% more power, yet it is significanly slower in the 1/4 mile and 0-60 than the RDX. Low end torque makes a difference, but it still seems off somehow.

I think it is making more like 270 hp crank.

 

On the "temple of Vtech' dyno test video, they did say that 240hp for the RDX was underated and in actuality pulled closer to 260hp.

Rusty

 

yes i agree it is underated but then again the dyno they did was only 2wd. Of course the readings are going to be higher than if it was run on awd dyno. Fwd = less drivetrain loss.

 

Very happy with my RDX turbo 4. I have found that with milage (I have 5100 miles) and experience the turbo 4 is a great engine. I have driven many V-6's and the turbo 4 on the RDX is more than satisfying.

 

A 4 cylinder works with certain applications, but the inline 4 of the RDX doesn't really deliver on what a 4 cylinder is supposed to have: good fuel economy. So, if you're not going to have the main benefit, why suffer with the negatives? I prefer the torque of a V6, the quietness of it, and the depth of it to a 4 cylinder not to mention the stronger power delivery at lower RPMs. Honda/Acura may build the best 4 cylinders in the business but it's still a 4 cylinder.

I think Acura made a big mistake with the turbo and should have put in a 2.5 liter V6 or, perhaps, even the inline 5 cylinder from the Vigor. Clearly people are not happy with the MPG of the RDX.

And as to building a lightweight car so as to compensate for a smaller engine... the NSX proved that this is a good strategy but that car is a performance track supercar. An SUV is not, and should not be a 'supercar.'

There is no replacement for displacement, I think.

 

Well... I was well aware of the mpg I would be looking at and I'm perfectly fine with what I'm getting now. And quite frankly, if someone finds it shocking what kind of mpg they are getting with this car, then they didn't do enough research.

 

You quoted CL6's sentence in context, but then responded to it ignoring the context. The dissatisfaction with the MPG is relative to the fact that it was marketed to be one of the advantages for going with an engine choice that has clear drawbacks in other areas.

 

I agree....I knew what I was getting into, but it still doesn't make me happy about it. If you're going to market a 4cyl for fuel economy, it should AT LEAST do better than a competitor's 6cyl...

Mike

 

While 'caveat emptor' should always apply, you are in the minority.

 

I think maybe the problem is the competitors all have direct injection engines now, and Honda has been slow to come out with those, as I understand it.

Someone can correct me, but I don't think the K series engine is direct injection while BMW, Toyota, GM and others have killer direct injection engines which are inherently more powerful and fuel efficient.

 

Kind of what I was saying. I find the lack of instant torque at times disappointing. I cant really complain about the gas mileage except that I think I could have had better power delivery with a larger engine with the same MPG.

I think a lot of people here have drank the "kool-aid" and are really not being objective at times about the car.

 

All of the speculation about "could have been better with..." aside, though I too share many of those thoughts - I'm still pretty amazed at what the little 4 under this hood can do (modulo not getting better gas mileage while doing it).

So, while it isn't the case that "this engine sucks" in an absolute sense.

And, while it isn't the case that "this MPG sucks" in comparison to the SUV landscape.

It's the fact that it "might have been a better driver with a 6 that could have had a more driveable torque curve for similar performance and MPG..."

 

So you prefer LESS torque? Only the 3.7L MDX motor makes more torque than the RDX. Have you actually driven an RDX?

The RDX has better low end torque than pretty much every Honda product ever produced, yet you guys want a V6? Results are God. Reminds me of the people sneering at the Corvette's leaf springs.

All the marketing I have seen is that the turbo was for performance.

 

Another thing I wanted to point out is that it isn't just the engine alone - the transmission also contributes to lack of instant torque. This engine with a manual, or a more instantaneous engine with this automatic - either may have been much more driveable, but this engine with this automatic combine to delay the onset of torque even further.

Having said that, I'm using S mode more now (not the fully manual, just shifting to S instead of D) and noticing that it is much sprightlier feeling around town with not much noticeable impact on MPG. Also, the last time I did some twisties I shifted into S mode a couple of miles into the run and the driveability got way better (still no match for better low-end torque, but much improved).

My impression has been that Acura decided to set the shift and boost maps to prefer boost over downshifts since the downshifting detracts from its upscale SUV image - and that boost is a less efficient way to make power when you need it. Using S mode around town shifts those maps back in favor of downshifting and so the mileage is around the same, maybe even better, and driveability improves, but the car shifts more. Personally I find the shifts so smooth that they don't detract at all from the ride...

One drawback of S mode - if you go onto the highway it will happily hold 3rd even with the cruise set at 80. I recall someone saying that it refuses to shift into 5th, but I'm afraid to find out what speed it decides that it can do even 4th. Need to remember to shift back to D for the highway stints or drink mass quantities...

 

I sold Acuras for 4 years and I've only driven about 125 RDXs or so but I'm pretty sure peak torque comes into play at 4,500 rpm. The CL Type-S automatic has 232 lbs ft. at 3,500 rpm. However, there is no turbo lag, the fuel economy is better, and the engine is quieter and doesn't have to work as hard.

Don't get me wrong, once the RDX gets going it's a blast to drive and has great power, however that process takes a second or two while not delivering on the raison d'etre of a 4 cylinder - better fuel economy than a V6. There is no way an inline 4 that's constantly having tons or air forced into it to squeeze out more power is going to be as reliable long-term as a larger displacement engine.

Acura can spin, no pun intended, the reasons for the turbo any way they want but, facts are, a V6 would have cost more, been heavier, and would have pushed it closer to the MDX or resulted in heavy development expense should a new 2.5 liter been developed.

Also, for those interested in tuning, the V6 has ample room in it to squeeze out far more horsepower and torque whereas the turbo 4 is in a bit of a different situation if reliability is important.

Finally, I'm sure the SH-AWD saps some of the 'seat of the pants' torque. That's not the engine's fault, however.

 

Sold as in "past tense"? Whatcha doin now CL?

 

Jumped to a different brand.

 

You can also paddle shift into 4th and 5th using Sport Mode.

I use the paddle shifters to pre-select the desired gear upon corner entry and have immediate throttle response at the apex.

 

LEX?

 

You can also engage the paddles when just in standard drive. Hit one of the paddles and it engages sportshift. Once you come to a stop you go back to automatic

 

German. 'nuff said.

 

No, I want the torque when I press the gas pedal. I guess my problem is that I dont use Hondas as the benchmark, I use German cars.

FWIW: I constantly make fun of the leaf springs under Vettes all the time. Like Jeremey Clarkson said; it still comes with exactly the same sort of suspension that you get on a Silvercross pram. Yup. It has leaf springs, which means it still rides like it’s running on wooden tyres.

 

If you want torque, get a diesel!

 

And yet it runs rings around most European cars on the track. Typical European crap. If it was in a Porche or BMW they would be talking about how clever it was. They work, and they work very well. The results speak for themselves. Corvettes are better track cars than most cars twice their price. And Jeremy is just playing to his audience--Europeans who want to believe they still make the best cars (they don't, $ for $ model vs model the Japs are better) and to contrarian grass-is-greener Americans.

Problem with German cars=$$$$. With a few exceptions they do not justify their cost. The current 335i (a turbo, by they way, that outperforms many V-8s) is an exception. It seems to be a pretty good value. I just feel that they always come up short once you factor in price.

 

Actually, it defaults to Automatic Drive Mode after about 6 to 8 seconds of steady state with no further paddle input.

 

Guess I never waited that long!!

 

The Vette is a great car with a horrible, cheap Chevy Nova interior. Even if you get the dash in hand stitched leather the plastic is still nasty rental car cheap. Aside from that, it's a winner.