Hi,
I'm currently shopping for a new SUV and I'm currently eyeing the RDX. I wanted to know if there is an eco mode or is there a way to save more fuel? I'm aware that with the price and value of the RDX compared to its competitors, the fuel economy is not that important, however, I'm curious to see if the RDX has it or not.

Thanks!

 

No economy mode. Its gas milage is not the greatest if thats what you are interested in.

 

They need to add a drive mode below comfort called eco mode that gets you the best gas mileage

 

That would be called a CR-V.

 

There is a “snow mode” that would behave much like eco. You could put it in snow mode.

 

comfort is like eco, no?

 

It still operates in AWD while in comfort, and while the shifting is less aggressive, the throttle response is still pretty quick. I think an eco mode would be more conservative with throttle response, maybe even less aggressive shifting, and for AWD models would just do FWD except in case of traction issues.

I guess eco mode might be a nice option for people who want to be more thrifty, but I think we’re only talking 1-2 mpg savings possible so it doesn’t seem all that important.

 

The AWD drivetrain in RDX is always engaged back to the rear differential, so the friction of the transfer case and driveshaft U-joints is constant.

Other manufacturers have developed systems that completely disengage the rear drivetrain when AWD isn't required, and this does yield modest fuel economy benefits. But you're still left with the additional weight of the AWD system.

Overall, the SH-AWD system in RDX is designed more for performance than fuel economy.

Now that I think of it, I don't know that owners are properly reporting whether their vehicles are FWD or SH-AWD in other threads on fuel economy. It does matter.

 

I'm sure they could add an Eco mode in a future firmware update. Slower shift schedule, leaner fuel, FWD only, mitigated turbo response or disable the turbo altogether except for extreme throttle command. And the vehicle becomes a complete slug and gains about 2-3 mpg.

How much of a demand is there in the RDX community? Are we screaming from the rooftops for this? How much would YOU use it? I might use it on long over-the-road interstate trips. Or, I might never use it at all. I don't know. I sort of consider Comfort as Eco ode.

 

My CR-V's were all much more fuel efficient than my RDX. One article I read some time back compared the RDX and the CR-V, a natural pair as it were. The reviewer did a great job on this and his conclusion was straight forward and honest: If you want more interior space for hauling things and if you want better fuel economy get the CR-V. If you want a more sporty drive and more comfort and can put up with a bit less interior space (luggage in the back) get the RDX.

As for the CR-V and its green "Eco" button: It does NOT change the fuel mixture. What it does do is slow down the throttle response, shifts to a higher gear ratio quicker and dials back the AC system to save on power and use less fuel. (Some CR-V owners complain about poor AC operation not realizing the Eco mode is doing this!) I got better economy without using the Eco mode as when its on many people just push harder on the gas pedal which defeats its function. I have always thought of it more of a gimmick than a real help, at least for anyone that knows how to drive a car to maximize efficiency.

My CR-V was much, like a lot, more fuel efficient than my RDX. I would guess it got about four or five more MPG. Both were AWD. My 2017 1.5 Turbo CR-V was much more fuel efficient than my 2012 2.4 CR-V. My 2019 RDX is not quite as easy on fuel as was my 2012 CR-V. BUT, the big difference.....the RDX is just so much more powerful and spirited to drive. Nothing in life is free! I got over the lower MPG and learned to just enjoy the car. If you want maximum fuel economy in this size car just buy the CR-V.

 

Thank you all for your replies. I currently own a 2012 CRV and you're right about that there is a price to pay for the performance of the RDX.

 

Mine is getting mileage like my V8 Lexus LS used to get... If MPG is a concern I would read up some more on the RDX. I drive in comfort mode like a grandma and get around 19MPG with a FWD in Cali weather.

 

If I drive "normally" ( conservatively ) my AWD RDX easily averages 25 to 26 MPG. If I am driving in the city and like to zoom around it drops to 18 MPG ( I can make it get better in the city if I work at it) . If I am on the flat lands, no wind and driving at say 65 or so, smoothly, it has done better than 30 MPG for a full tank with 32 or 33 being the highest ever.
I won't compare it to a V-6 or V-8. After all, this thing can make a lot of horse power and making all that horse power takes lots of fuel. I find the largest impact on the economy of this car is ME and my foot on that gas pedal.

 

I was looking at some of the other Acura Models and they do have eco-mode as well. Its strange that they didnt include it in the RDX. But yea, I think overlooking the fuel economy, the RDX is really a great buy.

 

Yes I am for it also. All city driving I get like 9.2 which is really crap and I drive like grandpa. I can accept the few people in here that say oh it's a RDX and it was made for performance but how big if a deal is it to give eco mode. I mean do all of us that own a RDX need 2 sport modes? I for one only need one. I would be the first in line to get the firmware update to remove the Sport ++ or just the sport. Hell I bet they could just add another selection to the selector. to have 5 modes.

The city is supposed to be 20 MPG I would be glad is I got 18. Now I can say on the highway only in comfort I do get 28 which I would love to have 30 but I am happy with the 28.

Mine is a 2019 ASpec AWD.

 

We bought an RDX AWD earlier this year. Based on all the research we weren't figuring on getting great gas mileage. Due to corona we have only put 800 miles on it over the past 3 months we've had it, but our average MPG in comfort mode is between 23 and 24. It's my wife's car and she's no speed demon, but not a grandma driver either. It's not bad MPG for the power of the car I guess. Maybe the MPG will be slightly better as we put more miles on it, but I'm not counting on it. I find it odd that a relatively smallish vehicle with ~280HP gets slightly better gas mileage than my very heavy 2019 F-150 with a 380HP V-6. I'm getting 21 MPG with my pickup. I've seen no difference in ECO mode on the truck. I don't typically have large heavy loads in my truck nor do I typically tow a trailer, but 21 MPG's in my truck is pretty amazing in my opinion.

I'm not unhappy with the MPG on the RDX because we did the research before hand. A little off topic - If there was one thing I would complain about on the RDX it would be the ride in comfort mode. Even in comfort mode it rides like a damn lumber wagon. I live in the North East and the roads are brutalized by winters and the towns and state don't take care of them. So the pot holes and bumps are very noticeable in the RDX. I just with they would have softened up the suspension more in comfort mode. But it is what it is for now.

 

The engine and transmission are performance oriented not geared toward fuel efficiency.

 

Eco what...? Dont care 😀

 

2012 Honda CR-V is a smaller car. RDX is 3.2" wider, 8.4" longer and 478 lbs heavier. Be careful with Snow Mode - Cruise Control and Engine Auto-Stop won't work.

I'm not sure what ECO mode would do. Car operates already at very low revolutions in Comfort Mode. Limiting acceleration won't improve mpg. With strong acceleration fuel usage vs time will be higher but fuel usage vs road traveled will be lower. Records of best mpg are made by rapid acceleration and coasting (full load or none). The biggest waste in aggressive driving is from braking and higher average speed.

 

Yeah, this car uses a detuned version of the engine in the CTR and specs out higher than most competition in this class. The focus on economy seems out of place.

 

Eco mode could cut out about 40 to 50 hp and save gas. I do coast a lot from red light to reg light. Unfortunately true city gas millage is crap. Speed limit is 25 in the city with many speeding and red light cameras around so $50 a pop if they catch you.

I am 100 % confident Acura and Honda could roll back the hp on the car with ECO mode and not turn down the idle.
Me personalty I think they used San Fransisco down hill as a city gas mileage test not real city driving.
ECO mode on a Honda cut throttle response.

I will have to try Snow mode and see if what you state is true about auto stop and cruse control.

 

It depends how they do this. To obtain more efficiency they need large engine that becomes small (Honda V6 switches half of cylinders off), or small engine that becomes big/strong when needed (Turbo). ECO mode in my Accord was a joke. It made cruise control acceleration very slow and if it saved any fuel it was because average speed got lower. Perhaps they could manipulate injection somehow, but it is already very complicated.

 

This is simply not a car for economy. Other cars do that, not this one.

 

That’s just absurd. Nobody is saying this thing should get mpg like a Prius, just that maybe it would be nice to adjust the response to make it a little more efficient when sportiness is not necessary. If the Jaguar F-Pace can have an eco mode, surely Acura could too.

 

Jaguar might have ECO mode, but the question is if it really works. Most of the time lower fuel consumption is due to lower average speed, caused by reduced acceleration. You can obtain the same without any "ECO" mode, by just driving slightly slower (to match lower average speed in ECO mode).

 

I believe in the case of the Jag, it also affects transmission behavior to have it upshift earlier as well. In some other cars, it will also affect when the car makes boost, and how much boost it makes, which is a huge factor in fuel economy for turbocharged cars.

 

It comes back again to reduced acceleration, meaning lower average speed hence better MPG. I can do this by just driving slightly slower. I would like to see MPG improvement with the same driving (same acceleration) otherwise it is BS. If it can be done without reduction in performance then why it has to be special mode?

 

Something could be done with the AWD pretty easily to improve mpg. I mean, this is the fancy SH-AWD that can send 100% (of 70%) to either one of the rear tires or something. So surely it could keep 100% of the power in the front to squeeze out a little more efficiency...

 

It is possible, but at the expense of safety, IMHO. I feel much safer knowing that car delivers power to all wheels all the time - that's why I bought this RDX. Many other AWD SUVs are FWD most of the time switching to rear wheels only when front wheels loose traction (already too late).

 

The transmission can short shift while still maintaining the same level of acceleration (performance). Now, you'd probably ask why wouldn't it do that in normal mode since there's no reduction in performance? Well, there is when you call for more power; it would need to downshift more gears and thus respond slower. We know that in sport mode the car will hold gears longer (which inherently burns more fuel when traveling at the same speed). Is it a stretch that the shift logic could go in the other direction (shift earlier) when in an eco mode?

 

I'm not sure that car burns more fuel in Sport mode. Fuel consumption is related to load on engine and not the revolutions itself. With the same load at lower gear engine works at higher rpm but is subjected to lower torque and less fuel is injected per revolution. Driving in Sport or Sport plus mode might increase fuel consumption only because people intend to use these modes for more aggressive driving, that involves a lot of braking (energy loss).

 

We have ECO mode in our 20 CR-V 1.5T. It is useless, not only makes acceleration doggy, but limits the A/C compressor use, and after you suffer through all that, no obvious improvement in mpg! We used it once, and never again. Others on the CR-V forum concur.

 

We have a very easy way to test your theory. Go cruise on the freeway in 3rd or 4th gear for half an hour, then do it in 9th or 10th, and see which one burns more fuel

 

It will be the same, unless you think that energy escapes somewhere. The purpose of operation at lower revolution is to reduce noise and improve engine longevity. My friend did what you offered. He drove car over 10hrs from Canada to my home and back. On the way from Canada he drove on 3rd gear of 4AT (no overdrive button was pressed by mistake) and on the way back drove on 4th gear. Fuel consumption was identical (I asked him to check). I drove RDX at first in Sport mode and now in Comfort mode. Fuel consumption is the same. Engine is not getting better efficiency when operating at lower rpm.

 

Energy does escape in the form of friction. Higher RPMs have higher frictional losses. But don't take it from me:

https://www.roadandtrack.com/new-car...-fuel-economy/
https://money.usnews.com/money/blogs...t-drivers-make
https://www.caranddriver.com/feature...-fuel-economy/
https://www.metrompg.com/posts/rpm-mpg.htm
Sorry, but if you bring that story to any hypermiling forum, you're going to get laughed out or straight up called a liar.

 

Yes, there will be some loss on the friction in cylinder, but remember that at the same speed and higher engine revolutions torque will be proportionally lower putting less stress on bearings etc. - hence less friction. Also, 90% of power at decent speed goes to fight wind resistance. Engine friction losses are small in comparison. Your chart would suggest, that since fuel consumption from 2500 to 5175rpm almost doubled from 5 to 9.08 l/100km, most of the fuel consumption was cased by friction and not the wind resistance (or rolling resistance). It does not make any sense.

With constant speed there will be constant power demand on the engine. Power is torque x speed. If you increase speed by two required torque will drop also by factor of two. Amount of injected fuel is proportional to force on the piston (torque). Engine will work at higher revs, but use less fuel per rev. People assume that more combustions means more fuel burned, but amount of fuel per combustion is straight proportional to resistance (torque). Most of engines have sweet spot (lowest fuel usage) at about 3000rpm. Engine will use more fuel at higher and lower revolutions, but not by much (curve is pretty flat).

 

I also found this discussion: https://www.researchgate.net/post/Ca...RPM_tachometer

Here are two quotes:
"I do not think there is a relation between fuel consumption and tachometer reading. As a matter of fact engines consume more fuels when running at low speeds and very high speeds. In between there is a speed where fuel consumption is minimum and that speed is called the economical speed of the engine and it differs from engine to engine."

"RPMs and fuel consumption have only a very slight correlation. (As higher RPMs correlate with an increase in friction losses.)"

 

We have it on our Accord, and it is equally useless. We have completely stopped using it.

 

Dead on. It's rated at 20 mpg city. It would be nice for it to get 18 -19 in the city. I know it could never get 28 to 30 in the city, but 9 to 14 is ridiculous.

 

I had it on a rav 4 and I always used it in the city. Yes is was slower but I knew that. I really don't need to got fast from red light to red light.