1 .. 91 oct .. 12.1L/100km .. 19.5 mpg US .. city, comfort mode

2 .. 91 oct .. 13.1L/100km .. 18.0 mpg US .. city, comfort mode

3 .. 91 oct .. 10.8L/100km .. 21.9 mpg US .. hwy, comfort, 4 lane mountain hwy, much extended hill climbing, 130 km/hr (80 mph) for most

4 .. 91 oct .... 9.1L/100km .. 25.8 mpg US .. hwy, comfort mode, much less hill climb, more 2 lane passing. 110 km/hr (68 mph)

5 .. 91 oct .. 10.2L/100km .. 23.1 mpg US .. hwy, comfort, 2 lane, 110 km/hr typical

6 .. 94 oct .... 9.0L/100km .. 26.1 mpg US .. hwy, comfort, 2 lane, 100 to 110 km/hr typical, returning to sea level


Typical elevation was 1200 to 1600 feet above sea level for tanks 4 - 6. Tank 3 was elevations up to 4800 feet asl. City driving is mostly 0 to 400 feet ASL.

RDX Sh-AWD Advance mileage
 

After a month of driving I 'm getting 23.6 Around town. On a 230 mile round trip (Eagle, Idaho to McCall, Idaho via Hwy 55) with twisty mountain road average was 29 MPG!

Wow how did you manage that? I have reset my trip meter and was going 50 or 55 miles per hour on flat Illinois highways and the most I could get was 26 MPG. The most I can get with just city driving is around 20 MPG.

All I can say is that dont buy the RDX for fuel economy. It is actually worse than my 2014 RDX. I find that odd since it is a 2.0 4 cylinder and no matter how I drive it, it just doesnt get good milage. Both of my Porsche get far better gas milage than the RDX.I knew it wasnt going to be great milage but it is a shame it didnt improve or have some significant improvement. If the milage had improved, this would have been a much better reason for people to purchase. Acura may have missed the mark on that main feature.

If it is any consolation, per Fuelly, it gets about the same fuel mileage as the Chevrolet Equinox with its' 2.0L Turbo 9 spd auto & AWD.

It gets about 2.0L/100km (4 mpg) better than the new Subaru Ascent with its' 2.4L Turbo and also the Mazda CX-9 with its' 2.5L Turbo. I know, bigger heavier vehicles, but it shows the RDX to be typical for turbo 4 cylinders.

.

It's actually not that odd for a TURBO 4 cylinder to get worse mileage than a naturally aspirating v6 when you consider how they map for peppy torque at the get go. Anywhere you're in boost you're really not getting any good mileage. Cruise is about the only time, and that's really only if you stay out of boost. So that's where more gears is supposed to help but really how many of us stay that static on the freeway? Coming from subies, i expected this kind of mileage. We had to stay under 3k rpm to get any decent mileage.

Yep, 'turbo' and 'good mileage' should never be used in the same sentence.

:drag:

Before the fuel up. I hope I can keep this MPG average (although I know the trip computer is off by a bit). Someone mentioned Fuelly earlier, and I've been using that app since I got the RDX and what I think what is happening is people love driving this car, and not conservatively haha. It's a fun SUV to drive and some might have a bit of a lead foot, hence the 22.8 average MPG on Fuelly. At least, those are my thoughts.
https://cimg6.ibsrv.net/gimg/acurazi...480e2ae267.jpg

The figures I posted earlier were calculated, not from the HUD. The HUD is a bit optimistic.

I try to fuel up the same everytime.

Calc vs HUD L/100km (lower is better)

12.1 <> 12.1
13.1 <> 12.5
10.8 <> 10.5
9.1 <> 8.7
10.2 <> 9.8
9.0 <> 8.8

.

Update after 4000 miles
 

How's the ride with regular? I'm in California and I feel it every time I'm at the pump.

You know, I'm in LA, and we have pretty high gas prices, but the premium is still only what .30c more than the regular? So, at most 17 gallons x .30c = $5 more per fill up? Even if you drive a lot and fill up a full tank every week thats $260 extra a year. It's not THAT bad. (I'm trying to justify still putting in premium in my RDX haha)

I only put premium in my RDX, you do not need to justify to yourself, or anyone else for that matter, what grade of gas to use. If your content, that is all.

I haven't seen any difference between REGULAR and PREMIUM.... If you're engine isn't knocking, Premium isn't going to help. My highway MPG is virtually the same as City. Not happy, no wasting money on premium.

I don't think this is quite right, the RDX has a recommendation for premium with a minimum for 89 (or is it 87). This means that the engine control unit has the latitude to adjust the spark timing and turbo boost to run the engine without knocking with the lower octane, so use 89 octane if you want, but the spark timing will most likely be retarded and the max boost be lowered . The rated horsepower and torque are measured using 91 octane so, you are correct that premium isn't going to help prevent engine damage from knocking any better vs regular, but you should get better performance and mileage with premium (published specs).

Now if you had a car without knock sensors that runs fine with regular, then there certainly no advantage to use premium. In the same vein, even if you have a modern car with knock sensors but the engine management can't advance the timing enough to extract more power, then again, there would be no advantage to running premium.

This past summer, when gas was at about $3/gal, premium was about $3.69/gal - top tier grade, filling up with regular saves quite a bit of money.

Premium is recommended, if you are spending $40k plus on a vehicle, you shouldn't be whining about gas prices, sure, it sucks, but guarantee this car runs better on premium. The only way I would ever put regular is if I was going on vacation and knew I would burn up the tank on the expressway.

Yeah, it still boggles my mind that people with these type of cars don't buy 91 oct or better.

1. If you drive 20,000 miles per year, that's 1,000 gallons or less, so the savings per year would be $300.00 or less. If you need to save $300 each year by using a fuel that your engine wasn't optimized for, buy a different car.
2. The gas shouldn't be named regular or premium. Octane rating is the fuel's resistance to knock, different engine designs are optimized for different fuels. The compression ratio, ignition timing, and boost in the RDX is optimized for a higher octane fuel. I didn't same requires because the ecu can change the ignition timing to accommodate a lower octane fuel, but it's not ideal. You'll loose power, fuel economy, and in some cases, engine longevity (not like the old days when your engine would die very quickly and dramatically with the wrong fuel, but there is some anecdotes about engines lasting 100k miles instead of 200k+ miles, depending on the car of course).
3. Why pay for the RDX when you could get a cheaper car that has as much power on regular as the RDX is reduced to on regular?

Uhg, sorry for the typos, I don't have enough posts to edit, it seems.

This debate on regular vs premium boggles my mind. Go buy something less expensive that runs on regular and be done with it. Perhaps the RDX price point is not for you.

The accord has a similar 2.0l turbo engine. It seems like gains are achieved when using 93 octane even though they recommend 87. I doubt it hurts to use 87 in the RDX and you would see similar gains/losses in performance if you switched to 93 or 87. The RDX isn't a sports car where every hp or lb/ft of torque counts, so if you just want a comfortable ride, I can see why someone would question the need to use 93 or 91 and burn an extra $5 a tank for what basically amounts to nothing to them. Take that extra $2500 saved after 10 years and buy a new engine for your 10 year old car that you just 'ruined' using 87 lol

I'm pretty sure most received a vehicle filled with 87 when they picked it up and couldn't tell the difference as much as they think they can.

http://www.ktuner.com/dyno/AccordX/2L/93vs87Stock.png

An old world example. We bought a new '96 Volvo 960. The dealership gave a class for new owner( a hint as to how much over priced they were). The head mechanic spoke to us about several things, one of which was regular vs premium. He told us that using regular was fine and would cause no engine problems. But as an example of the difference between regular and premium, he was driving down I-95 pulling his boat. He was running regular but could only get up to about 60 or 65. Since he was running low on gas he filled up with premium. Then he could drive as fast as he wished. Per him on Volvo it's just a power thing no engine problems.

I run premium 'top tier' from a local station and 'top tier' when I can find it conveniently located on a trip. I don't think the 'top tier' designation affects mpg in the short term, but it is supposed to run cleaner with fewer deposits over time and does have a quality standard supposedly to be able to be labeled 'top tier'.

After 2 fill-ups with mixed city/highway (southern california) my avg MPG is 24.46

Just a few tanks so far--60/40 local/highway--in Comfort and using premium top tier fuel, averaging 22.6. I expect that will improve as more miles get added. But the car is great to drive that's for sure.

I have around 940 miles, on my third tank, I am averaging around 20mpg, usually drive in sport mode, 93 octane, don't go crazy, thought I would be doing a bit better, my S4 6MT was only a bit worse

Been using Costco - Kirkland Signature Premium Fuel; it's rated at 92 octane. I live in Seattle and driving has been about 50 highway / 50 local roads.
https://cimg8.ibsrv.net/gimg/acurazi...0a5b945fb8.jpg
https://cimg9.ibsrv.net/gimg/acurazi...bba73d607f.jpg

Just going by what the computer says I'm at 20 mpg almost 100% city driving during my first 600 miles, driving with a feather foot. I fill 91 (that's the best we get in CA) and drive in sport mode. I expect to continue with feather foot, not much motivated by flooring the gas pedal. For fun, I like to feel what's coming through the steering, and also occasionally play with the paddle shifters in sport+ especially on slopes.

First drive MPG .. 99% highway driving with dealer filled-up gas (so probably its 92). 100% Comfort mode.
https://cimg4.ibsrv.net/gimg/acurazi...2c96e92ef.jpeg

@Coolguy, what kind of speeds were you predominately driving to get 30mpg, 55, 65, 75mph?
Thanks

mostly 65 and sometime 60. But remember, its only 10 or so miles local roads and rest highway. In last 2 days MPG has dropped to 26 due to all local driving.

Wow 30 mpg with awd is really good. I also have awd and got 23 with mostly highway driving of around 100 miles. Only 5-6 miles was city traffic. But I drove in Sport mode and between 65 - 75.

Mine is a SH-AWD with almost 50000km (~3000 miles). Mostly a mix of both city and hwy driving (but rush hour traffic since my wife drives it to work) and it's averaging about 11L/100km or 21mpg. Not the most efficient car but notably better than the 07 RDX AWD that we had previously, which was getting 13.8L/100km or 17mpg.

One observation, looks like the car is burning up lot of gas during idle/slow speed. Idle rpm/speed is also seems to be higher then all previous cars/suvs I owned.

Performance Red ASPEC with SH-AWD
 

I picked up my car on Oct. 20 I didn't track my first fill-up, but on my second fill-up...
Nov. 2, 509 miles on the odometer
304.6 miles since the last fill
15.487 gallons to fill it up
19.67 MPG average

I live in the Bay Area so it's a pretty good mix of city & freeway driving. I drive in comfort mode 99% of the time. The auto off on idle was sometimes on, but most of the time it was turned off.