Acura RDX Fuel Efficiency Concerns

nycgirl1024nycgirl1024 Member Posts: 1
edited July 2014 in Acura
I started looking at the RDX in mid-August. I fell in love with it. I drove it a week later and was basically sold on the car. My fiance and I put a deposit down on the car and now we have just been waiting for our Acura dealer to locate the type we want. The other night we started reading all of the posts about the fuel efficiency and we are horrified. We went from being 99% sure we were going to buy the car to about 80% sure we are not going to buy the car. Can I get some feedback on the fuel efficiency? Who thinks that the 13 MPG that a lot of people have been getting is the norm rather than a few exceptions? For those of there out there who are thinking about buying the car, how much is this a factor for you?


  • robertsmxrobertsmx Member Posts: 5,525
    There aren't a lot of people claiming to get 13 mpg. If magazines that seem to be pushing the vehicles to explore its limit are doing better than people driving on a daily basis, there is something wrong. Motorweek observed an overall 21 mpg, which isn't too bad, probably what I would expect.

    If you're wary of mileage, but love the vehicle, I suggest waiting a little and look for more people and real world mileage rather than basing it all on couple of posters comments and a few leadfooted road tests.
  • cwatt998cwatt998 Member Posts: 3
    Nice feature on the RDX that when you reset the trip odometer, it resets the average mileage. I reset mine tonight before I picked my son from the airport and home in my non-tech with 1300 miles.

    Trip was 8 miles on secondary roads at 50 mph with two stops then 21 miles of interstate, changing highways twice and trying to maintain 70 mph. Total trip was 58.1 miles and the computer showed 24.9 mpg.

    Same trip in my 2001 RX300 would have given me 19.
  • c_hunterc_hunter Member Posts: 4,487
    I share your concern (though I have not gone to the added stress of putting a deposit down). We have gotten good and bad mileage reports, for instance the good report from cwatt998 (albeit relevant to a specific type of road trip). Unfortuntely, none of the reports will guarantee how the RDX will do for you and your driving style. Since there is a wide spread to the data, I feel like it is still a gamble.

    I do not want to dismiss the low MPG numbers from the car magazines simply because they drive the vehicle hard. Other vehicles do OK under the same driving conditions, so it's not a good excuse for the RDX's mileage dropping 30-40% below the city rating. I think that's just too low to be explained by spirited driving. I have a similar engined/powered vehicle rated 19/24 and I have never been able to drop the MPG below 18mpg even when doing mountain driving with 4 people in the car and all their gear, during a snowstorm no less!

    You asked how much of a factor the uncertain MPG is to me, and I will tell you that it has me sitting on the fence about the RDX (and also has caused more interest in the upcoming 07 Honda CR-V). It's also made me think the typical 20-22MPG I get on my Outback XT is maybe not so bad afterall! I love the concept of the RDX, and aside from a few minor complaints it would appear to be a great vehicle for me and my wife. But there is no way I am going to change to a vehicle that has questionable gas mileage at this point. It's too important of a factor for me.
  • robertsmxrobertsmx Member Posts: 5,525
    I do not want to dismiss the low MPG numbers from the car magazines simply because they drive the vehicle hard. Other vehicles do OK under the same driving conditions, so it's not a good excuse for the RDX's mileage dropping 30-40% below the city rating.

    You're assuming same driving conditions. Some cars are pushed harder than others, more so if you're curious to figure out and curious to explore the limits. How do you think Motorweek obtained 21 mpg?
  • c_hunterc_hunter Member Posts: 4,487
    No comparision will ever be perfect, but I don't think you should keep making excuses for the RDX -- people are concerned about the mileage reports and those concerns should not be downplayed. Even if you question the raw numbers, there is no disputing that MPG data is all over the place, and not exaclty confidence inspiring.

    BTW, Edmunds got 11mpg in their review...
  • robertsmxrobertsmx Member Posts: 5,525
    Its not about making excuses. Its about being fair and realistic. Something Edmunds does mention is their leadfootedness. Wouldn't it be fair to consider that aspect?
  • patentcad1patentcad1 Member Posts: 69
    >>Something Edmunds does mention is their leadfootedness. Wouldn't it be fair to consider that aspect?<<

    Umm.. yes.

    Read the reviews posted by owners like me. I'm averaging 20mpg in mixed driving. To get 11mpg you'd have to HAMMER the car and drive around San Francisco's hills after sitting in urban traffic all day. That's ridiculous.

    I shared some of these concerns. After a week and 400 mi with the car I couldn't be happier. GREAT vehicle. And 20mpg for a 3900 lb SUV that goes 0-60 in 7 secs. is actually outstanding. Do the research. Other SUV's and AWD wagons are generally worse - and most of them are slower.
  • idridr Member Posts: 4
    We've had an RDX for about 1 month with 2300 miles so far. Btw city 30% and hwy 70% I get about 14 to 15 mpg. I don't know how others are getting 20 mpg. I'm not very hard on the gas pedal and I'm not rushing from point a to point b. If I knew how low my gas mpg would be, I'd probably would've chosen an X3 instead.

    I'm also bring it in for a problem already. During a complete stop, my car does not accelerate smoothly b/c the turbo kicks in either too early or too much all at once and you get a thrust rather than a smooth acceleration.

    Once the car gets going, it runs rather well.
  • robertsmxrobertsmx Member Posts: 5,525
    You might want to contact Acura or report mileage as an issue. It doesn't seem normal, given that even automags that always flog vehicles have achieved better mileage than you.
  • mdrdxmdrdx Member Posts: 2
    i got my rdx for almost 2 months and put 2700 miles on it. my daily driving consists of 30% city and 70% hwy ;) . its mgp is as expected, around 21 mpg.
    i.e 24 mpg at 55 mph, and 19 mpg at 75 mph.
    besides its ugliness :P , it runs pretty good and fast and quiet at cruising speed and on good asphalt. :)
  • patentcad1patentcad1 Member Posts: 69
    My mpg experience with my RDX (two months, 2500 miles) is spot-on with that or mdrdx's posted above. Precisely. And much of the time I'm riding around with a Thule rack strapped to the roof, which will make mpgs a bit worse....

    Oveall I'd say Acura's plan for using the turbo 4 to acheive better fuel economy has primarily failed @ the car magazine road test level - where journalists really flog the car to get a feel for its performance. Then they publish mpg results like 'we only got 16 mpg', the bloggers and forum floggers pick up on it, and it's off to the negative buzz races.

    But when you read the experience of 90% of the owners writing about their real world experience (like mdrdx and myself) the car appears to be a 19-20mpg car for the most part, with 22-24mpg on the hwy. Which is what EPA ratings of 19 city 23 hwy would lead you to expect if you understand the relationship of EPA ratings to real world mpgs on most cars.

    And yes the car runs good, fast and quiet (road noise is a bit higher than I'd prefer) on good roads. On bumpy roads the car is a bit stiff and jiggly. But it outhandles all the other SUVs. Those are your tradeoffs. So far I love it.

    It helps if you like the styling (inside and out). I do. Some don't.
  • mtairyordgemtairyordge Member Posts: 144
    Seems as though Honda/Acura has teh AC on as the default setting. I have had an accord for 4 years and now own a RDX and the AC always seems to be on. Yes I ma the only one who drives the car so its not being set on by someone else.

    Also the way the car is driven has a GREAT affect on the milage. If you keep engaging the Turbo then the milage goes WAY DOWN.

    Lighten up on the acceleration
  • johnny98johnny98 Member Posts: 88
    I've been averaging low 20s mpg with the AC on most of the time. That's half highway/half suburban streets. I think low 20s is decent for a vehicle that weighs almost 2 tons. The main reason some small SUVs get better mileage is their lower weight.
  • bcf15bcf15 Member Posts: 1


  • newdriver2newdriver2 Member Posts: 68
    I re-set the meter before I test drove the RDX. It was in the highway and it show 15.8 mpg which is really bad for a small SUV. Did anyone have the same issue? I didn't drive like crazy nor heavy footed the pedal. I have the AC on also.
  • varmintvarmint Member Posts: 6,326
    Depends on many factors.

    The first, and I'd guess most likely, is whether or not the engine was warmed up before you started the trip. I know from experience a warm engine can make a significant difference in the FE read-out for a short trip.
  • newdriver2newdriver2 Member Posts: 68
    I didn't warm up the car first but I drove it for 20 minutes. It seem warm enought to judge the mpg. How is your mpg? I am interested for this RDX but the fuel efficiecy is a big factor for me.
    The engine seem so busy. The interior is really when the car in idle. How does the relibility and durability of the turbo engine?
  • johnny98johnny98 Member Posts: 88
    I just got back from a 2 week, 3000 mile road trip with my RDX. I averaged 24mpg for the whole trip. That includes lots of mountains, winding coastal roads, etc. In flatter areas, I was getting 450 miles per tank of gas (about 27mpg) with the cruise control set at 75mph.

    Lots of cold starts, stop-and-go traffic, and fast acceleration will reduce your mileage significantly.
  • newdriver2newdriver2 Member Posts: 68
    Does anyone live in Manhatton, NY and have the actual MPG want to share? Or any people only use the RDX for city use only and have the actual MPG. I travel a lot in NY City and want to know the MPG before buying it, thanks.
  • johnny98johnny98 Member Posts: 88
    City driving MPG depends a lot on how long your trips are. All gasoline engines are inefficient until they warm up. If many of your drives are only a few miles after a cold start, then your mileage will be terrible in any car (and worse in a heavy car). The RDX is lightweight for an SUV, but heavy compared to a 4 cylinder sedan. On the other hand, if you only drive a few miles a day, then you aren't going to be burning much gas anyway.
  • frog22frog22 Member Posts: 24
    does anyone know if using reg gas will damage the engine, or create any other problems? I saw on Acura's website that they prefer premium fuel but that you can use there a downside to this?
  • ringzringz Member Posts: 1
    Yes, you must use premium. You can put the cheaper stuff in every once in a while, but long use of <91 Octane will damage the engine.

    I have had my RDX for 2 weeks and am getting 23.9 MPG for highway and city. I don't engage the turbo too much and use the AC in the afternoon/evenings. However, I also live in Florida so I don't deal with mountainous terrain.

    Take it easy on the pedal and avoid the hard brakes and you should get 380-420 miles per tank. Good luck!!
  • jc261095jc261095 Member Posts: 3
    Just to give a little more info about using premium fuel. Acura says that the care is tuned for premium but you can use other levels. For the TL, TSX even the MDX this would be ok. It is the Turbo in the RDX that makes you use the premium. It is all related to the Compression Ratio. Most cars will be around 8:1 and they run regular. The RDX says it has a ration of 8.8:1. Most high performance cars that need premium are around 10:1. If you did not use the turbo in the RDX at all you would be ok with a lower octane. However you will get better milage with premium. To restate frog22 "You can put the cheaper stuff in every once in a while" if you have to but best for the engine to keep with the premium.
  • newdriver2newdriver2 Member Posts: 68
    I know the Max. Towing is 1500 Lbs for the RDX but does anyone know how many Lbs the RDX could carry with inside. I heard the Turbo Engine couldn't carry much heavy stuff. Is that true? I like the car but never have any idea about Turbo Engine. The mileage for 2008 RDX is 17/22 which is really close to the MDX, why Acura will use the 4 cyc. instead of v6 if they get the same mileage? What is the advantage and disadvantage for the turbo engine?
  • rich4jrich4j Member Posts: 15
    I was at the dealer today asking about having to use premium

    I know a sales guy will say whatever it takes to sell but his message was that the mechanics say if you put premium in every now and then ...(maybe every fifth fill up) you should be fine.

    Only an issue when you start getting over 50K, 60K etc...

    Sounds like fiction to me?
  • wwestwwest Member Posts: 10,706
    The worse that can happen to your engine from the use of regular fuel is a low level of engine knock/ping until the ECU figures out the correct A/F mixture to prevent knock/ping and also adjusts the shift pattern accordingly to prevent knock/ping due to engine lugging.

    In the end the A/F mixture will run a bit on the rich side and the transaxle will be a bit quicker to downshift and/or not so quick to upshift into the next higher gear.

    The monetary result....???


    But you may very well burn enough "extra" regular fuel to make up for the money you "saved".
  • wwestwwest Member Posts: 10,706
    thought about hard-wiring the turbo wastegates into the fully open position??

    IMMHO the FE could be improved dramatically if the driver could somehow choose when the turboes are to be used, say not prior to 2/3's throttle or only with RAPID gas pedal depression.....
  • dlrsnitemaredlrsnitemare Member Posts: 3
    The under-powered CR-5...wife got's a good car and good gas mileage...I liked it but would have preferred the Turbo fired Acura....even with a little less gas mileage...Hell, my 04 Vette gets 28 on the highway at 80mph :)
  • ngauthie4ngauthie4 Member Posts: 1
    I am getting horrible gas mileage on my 2008 RDX. Is anyone else experiencing the same thing. Two of my friends bought RDX's at the same time and they are getting 18-21 mpg. I am getting 13 mpg and I drive like grandma. I am mostly city, but so is one of my friends. We are going to swap cars for a few days and see if there is a difference.
  • angelina247angelina247 Member Posts: 17
    I don't know how many miles you had on your car when you first wrote, but I have had my car a few weeks now and am getting better mileage than I did in the beginning (17.1 city now). I was initially getting about 13 miles per gallon. I hear you should get better mileage after 600 miles or so. Also driving too slow will actually give you less gas mileage, especially in the beginning . Something about "blowing out the engine" which will increase gas mleage. I'm sure someone on the board can explain it better than I can.
  • mark4490mark4490 Member Posts: 16
    I've only had my RDX for 3 weeks and I've only driven 1100 miles, but I'm getting ~20mpg. I think the other person that responded it right about not driving too slowly. A vehicle has it's maximum efficiency at a certain speed, say 60 mph. Go slower or faster and you're wasting gas.

    When I'm going up mountains or steep hills (i.e., Mt Tam in Marin), the fuel economy drops to almost zero when I'm going too slow. So I give it gas more gas to speed-up and my fuel economy actually improves. The engine is doing having to do less work since the RDX is already moving. I generally punch the trottle/ goose the turbo to get moving and then back off when I get up to speed.

    City driving reduces fuel economy dramatically. In my V6 Accord, I'd generally get 270 miles of city driving out of tank of gas vs 450 miles while on the highway.
  • wwestwwest Member Posts: 10,706
    Has anyone tried "wiring" the wastegate fully open to determine the FE improvement..??
  • aellinsaraellinsar Member Posts: 3
    Have you, wwest? You have been posting that same line on every Acura message board for the past 3 years. Why don't you try it and post some results.
  • wwestwwest Member Posts: 10,706
    Can't really afford to buy an RDX, or the CX-7, just to experiment. But should I decide to purchase then the CX-7 with DFI would be more likely. The DFI aspect would undoubtedly offer the most potential for FE improvment.

    Surprising that the RDX doesn't have DFI, soon to come..??
  • bgillette79bgillette79 Member Posts: 17
    Are you serious that you got 27mpg on the highway?

    Was the TRIP COMPUTER reading or MANUAL calculation based on how much fuel you had to refuel with?

    Hell...on flat highway at 75mph I'd be happy to see it get 24-25mpg!
  • 1bythesea1bythesea Member Posts: 52
    My '07 RDX with ~17000 miles on got 24.5 mpg driving 73 mph with the air running, on a mostly flat surface during a 700 mile round trip 95% highway last summer. Lately it has been averaging 20.9 with 50% city driving. Once summer is over, ethanol % is less, and resume to 30% city the mileage should return to average 22.5. These are all by the car readings, not by hand calculation.
  • mtairyordgemtairyordge Member Posts: 144
    On a recent trip to North Myrtle Beach from Frederick Md (450 miles 17.5 gal got 25.7 MPG)

    Yes this was manually calculated and I am positve about the number of gallons.

    Mostly highway (I95) till Wilson NC where backroads takeover.

    This was my driving.

    Around town, which for us is rural Carrol/Howard county, my wife consistently gets 22.5 to 23 MPG. This is also manually calculated.
  • Firebird_EOUFirebird_EOU Member Posts: 250
    Just came back from 300 mile trip avg 24.5mpg per computer with mostly highway 75mph w/AC - 2 adults. Normal in-town driving is 20mpg.
  • wwestwwest Member Posts: 10,706
    Drop the turbo and adapt the engine to DFI, 12:1 compression ratio, and the hwy FE would probably rise to ~30 MPG.

    Or even use Toyota's new HSD extended VVT-i technique to transition the engine from "Otto" mode into Miller cycle mode as the throttle opening rises. With the addition of DFI that would allow a 15:1 compression ratio for low engine loading, cruising, and transition to 10:1 to accumodate rising turbo boost with increasing throtte openings, acceleration or high enegine loads/loading.

    35 MPG and 300HP.
  • flytldrflytldr Member Posts: 2

    What's wrong with you?
    This isn't an 'engineer your own engine thread'
    Or a 'WIRE your wastegate open forum'

    Maybe you should spend some more time at your local community college, where
    your ideas can be exploited.
    Instead of suggesting people self destroy their $40,000 luxury vehicles!

    Good luck to you wwest!
    Stay away from open microwave ovens...
  • wwestwwest Member Posts: 10,706
    "...self destroy..."

    I'm comfortable, very much so, that anyone following my advice will have the knowledge to do so beyond the requirements of a community college.
  • flytldrflytldr Member Posts: 2

    Small town community college at it's finest!
  • steverstever Guest Posts: 52,454
    Anyone got RDX MPG to report?
  • wwestwwest Member Posts: 10,706
    Yes, for an I4, horribly POOR....!!

    Isn't the CX-7 due out soon with a non-turbo I4...??

    That will be a good point of comparison as to just how wasteful a factory turbocharged engine is, can be.
  • hms1hms1 Member Posts: 18
    Picked up a brand new 2010 RDX base 2WD in Atlanta last week and drove it directly
    Clearwater, FL. I was following a friend towing a jeep behind his truck so our speed never went much over 70. The highest the computer got to was 29.6 and the average, when getting home, was 28.4. I was really impressed. Don't know what it will be at my usual 75 to 80 mph highway driving. The city driving, which hasn't been much in this car this week, has lowered the computer mpg to 27.5. Still running on the gas purchased in Tifton, GA about 300 miles from Clearwater. Turned in my leased 07 MDX and even made $1300 on the lease. The car is for my wife, downsized for $$ reasons and purchased this time. Wife loves the RDX. Hooray! I like it too.

  • duncan01duncan01 Member Posts: 2
    I just picked up my new 2010 RDX last and did not realize that it required premium gas. That information may have changed my purchase of the RDX. Is it truly a requirement - has anyone use regular instead? Any negative issues with using regular?
  • wethertonwetherton Member Posts: 6
    With turbo, you really need to use premium. I just traded in a 08 tsx that stated premium, we put in plus for 49K and had no problem, but a local acura service manager told us it would be fine. That being said, I will only put prem in the rdx, we have 93 octane locally. At 20-25 cents more per/gal you most likely will get an extra 1-2 mpg which will make up your difference. Don't sweat the prem just look for cheapest/brand name gas in your area.
  • wwestwwest Member Posts: 10,706
    Required or RECOMMENDED..??

    With the advent/use of the new knock sensors the engine control ECU will simply enrich the A/F mixture if need be to prevent knock/ping.

    But you're in for some rather HORRID FE in any case.

    In order to accomodate the turbo boost when you use it the engine is derated when off-boost, 98% of the time for most of us.
  • wwestwwest Member Posts: 10,706
    Other than engine lugging, fuel grade, regular or premium, only makes a difference when you are putting a full charge in each cylinder, basically only when WOT. And how much time, overall, do YOU spend at WOT....?
This discussion has been closed.