Then you better not ever think of buying a rental or loaner that had my foot all up in it
I use loaners to tap into what normally I wouldn't do to my own.

 

My 2015 fwd has 16k on odometer , I'm averaging 27 mpg mostly highway driving, using A trip meter and resetting after fill up . I am using mid grade fuel.
Happy camper here also .

 

Just completed a 1300 mile round trip from MA to VA and back. Best tank of gas was yesterday from VA to fill up in NJ: 351.8 miles using 11.8 gallons or 29.8 MPG. Was 99% highway, avg speed was 67 MPH, no AC and regular unleaded. Was very pleased. Other fill ups on the trip resulted in 28.2 MPG, 27.4 MPG and 24.2 MPG, all primarily highway but some involved traffic on city streets and /or highway construction and congestion.

 

So, how do you know it's on 3 cylinders? I'm coming up on nearly 2 years on my '16 RDX Advanced and I would have to say is one of the best "rides" I've owned.

 

So true. And if you are operating the Adaptive Cruise Control and you 'rest' your foot on the gas pedal. it is going to screw your set cruise control up. I learned this recently. I was comparing the gas mileage of my 2016 RDX with that of my brother's 2014 Honda CR-V AWD. My RDX mileage was only 2-3 mpg less than his. I was pleased with that.

 

With the ACC, the slowdown is almost imperceptible. If I'm on the longest-range setting it is annoying. If I'm trying to maintain a pace that's higher than the car I'm approaching it is best to be "on your game" because if you've already pulled left there's a couple of seconds delay before the system notices and speeds the car up. If there's more traffic in your lane you'd better boot it. There goes the gas mileage. Overall, though, ACC is awesome on the short distance range in heavy-but-moving traffic.

28.5 U.S. Mpg on a long straight run, 27 if any issues like long hills or semis in the left lane. Premium in the U.S., Mid-grade while we're in Canada (nasty price spread to use premium, except at Costco).

 

In an attempt to achieve the best gas mileage possible, cruise control is always set when I am on the highway. I have my ACC set at the "second-to-shortest" setting which seems to work best for me. When I purchased this vehicle the salesman suggested that I would probably want it set at the shortest setting however I discovered that was outside my comfort level. I like to react before I am on top of someone's rear bumper.

Although Acura "Recommends" the use of high test gas in the RDX I sometimes use regular grade if I am just topping off my tank before heading off on a highway trip. However, and I read this here on Acurazine, if you have an engine that uses a turbo and the manufacturer states that high test gas be used, then use it if you wish to avoid engine problems down the road. When I do use regular grade gasoline with ethanol I get no pinning and see no difference in my gas mileage. The price of regular grade gasoline here in Canada has dropped this summer and is now $.95/litre or approximately $4.40/ imperial gallon for regular grade and $4.65/ imperial gallon for high test.

 

Pretty much the same.

Over a 300 km run (I reset the B trip meter) at a true 100 KPH (62 MPH), I got 7.9 liters / 100 km or 35.8 MPG Imperial or 29.8 MPG US.
Not bad for a large vehicle. Impressive!

That is a lot better than my first-generation Honda CR-V with a 2 liter four-cylinder engine and five-speed manual. But not anywhere close to my previous VW Diesel.

 

I have done quite a bit of highway driving this summer and consistently get 7.5L/100Km. That translates to 37 - 38 mpg (Imperial). My 4-cyl Honda Accord Sport did not get better than that. For a vehicle of this size and a 279 HP V-6 engine I am totally impressed. Although the trend is for manufacturers to move to 4-cyl turbo engines, I can't imagine such an engine giving better mileage than what I am now getting with my 2016 RDX

 

Good point and to be taken into account when doing comparisons on this thread.
Also, the temperature plays a big factor.

 

I'm a bit stumped by these results. Drove from Wichita, KS to Des Moines, IA last weekend. Temperature in the mid-80s both ways, no wind, consistently driving 80 mph except in construction zones.

Mileage going up was 24.5 mpg making the entire trip on a single tank of 10% ethanol. Mileage driving back was 29.0 mpg after buying a full tank of gas in Des Moines and adding half a tank in Kansas City with gas that "could contain up to 10% ethanol". What I suspect is that the gas purchased coming back contained more like 0% ethanol. All mileages were obtained using the "Current Drive" mileage for each leg driven.

Gas prices also seemed to reflect the energy content. Prices in Wichita were lower than Kansas City and Des Moines for a change. We're usually the high cost option.

 

Doesn't that just give you the mileage since the last time you started the engine?. If so, then the mileage on the outbound trip was for the entire trip (391 miles), while the mileage for the return trip was only between Kansas City and home (195 miles).

In this case I would expect the shorter trip would have given the lowest mileage, because the driving within the city would have been been a higher percentage of the total mileage. So your assumption about ethanol content may be correct, but I would be surprised if they put in less ethanol than they advertised.

I have set my RDX to reset the TRIP A computer automatically whenever I refill the tank. I also record the mileage from every single refill in a spread sheet. I think that comparing mileage from individual trips can be misleading. For example (an extreme example) is when I refill at the station and drive to my home, up a hill 2 blocks away, I will get 9.8 MPG on that trip. If I then get on the highway I will see the average mileage start to increase. If I make a 10 mile highway trip the mileage might increase to 18 MPG but as I continue to drive 100's of miles the mileage might increase to my all-time best of 28.8 MPG.

 

Not quite. The return trip was two legs - Des Moines to Kansas City and Kansas City to Wichita. Both legs just short of 200 miles, almost all of it at 80 mph except for construction zones, and showing 29 mpg for both. Not more than 2 or 3 miles of the driving was city driving. You make good points. I have Trip A set the same way. I had calculated the mileage manually for the first few months of ownership, confirming the trip computer is spot on, and then quit. I probably should have been keeping track the full time, as I've lost the history. The vehicle does get better mileage now than it did in the first 5,000 miles or so, however. It's a bit of a crap shoot given the changes in gas quality during the year. Not that I care that much. It's just interesting information - to me, anyway.

 

If I assume that my manual calculations are correct, I find that the RDX reports 4.7% (on average) better than I am actually getting. That is based on 115 readings that I have recorded over the last 2 years.

That may be because I put a little more gas in after the automatic shutoff (rounding to the next dollar), but I think that would all average out in the end.

Another possibility is that the trip computer shows mileage is off the top of the graph when accelerating, and yet doesn't read anything when it's idling. We all know that idling should produce an infinitely high MPG reading. Someday I will have to just start the engine and let it idle for a while to see what effect it has on the Current Trip MPG.

 

Putting extra gas in makes no difference. Gas mileage is calculated by the trip computer the same way you do it by hand: distance / fuel consumed. It has nothing to do with how much fuel is in the tank.

The trip computer shows very low mileage when accelerating. Idling produces 0 mpg, since you're not moving but using fuel.

 

I think the confusion is due to the different measurement methods between the US and Canada.. You use MPG and we use Litres/100 KM.

If your fuel economy improved from 15 MPG to 30 MPG, that would work out to be a change of 15.7 litres/100 KM to 7.84 litres/100 KM in our system. In your system bigger numbers mean better economy, but in our system bigger numbers mean poorer economy.

If you look at the trip computer of the RDX, your graph will sit at the zero end when idling, and move to the right when you get better fuel economy. When driving you would attempt to keep the graph as high as possible.

On our trip computers the numbers on the graph also increase towards the right, but as I mentioned, higher numbers mean poorer fuel economy. When we drive we attempt to keep the graph as low as possible.

Now this is the confusing part, when I am idling the graph stays at zero, just like yours. But 0 MPG is bad consumption for you and 0 litres/100 KM is very good consumption for me. That is what I meant earlier when I said that idling does not show any gas consumption, and that is why I thought the trip computer was producing better than calculated consumption values. It might just be omitting fuel used during idling.

Here is an image of your trip computer from the owners manual and a photo of my own which I took while I was idling.
Your Trip Computer
My Trip Computer

 

If you drove on the other side of the road, it would make even more sense ;-)

 

There are too many variables to get a meaningful number unless you are on the highway at a steady state.

Conditions:
Flat terrain - two-lane highway.
Cruise set to a steady true 100 Km / hour (62 MPH).
Trip B zeroed once steady speed was reached after entering the highway and pic taken when getting off the highway.
Temperature 26C (79F).
Distance travelled: 33 kilometers (20.5 miles) to my favourite pizza joint.

6.7 l /100 km (42.2 MPG IMP or 35.1 MPG US).
Temperature seems to have more of an effect than I expected.

 

My wife, who does mostly in town driving never reset her fuel economy once and she averaged 21.5 mpg. I reset it and I do 70% interstate driving and have been getting around 25mpg. 91 octane(ethanol)