MMike1981

1hr 15 min trip to my summer house this weekend, avg speed 57 mph...highest i got was 21.8mpg, 1 passenger, 2 duffle bags. 5500miles on the odo i didnt pay attention for the trip back home

mav238

Well, at the rate the gas prices are going up, it will probably not matter too much how one drives the RDX, at around 12L per 100km, it isn't exactly a frugal car...

I have chosen to take the public transportation to work, and use the car just on the weekends or the occasional night outs with the family... It is a little inconvenient to go to the bus station every morning and also missing driving the RDX...

But the gas prices does not seem to be letting up at all... predicting it to hit $1.50 a litre here in Canada in the summer, or $4.50 per gallon in the US.

portwashguy

Obviously you are not properly calculating your gas mileage. You must wait until you car hits 50 mph, is on level ground and drafting behind a truck and then you reset the mid gas mileage meter and measure your gas mileage for precisely 45 seconds and based on that state what your highway mileage is.

MMike1981

what was i thinking

mav238

Alright......

There has been a long debate and discussion on what the "true" mpg is for the RDX.

Let's talk about mainly regular city type driving, and not about empty freeways... the latter is great for mileage but is not realistic and does not represent the majority of the folks who drive to work. Even typical freeways at typical rush hours are somewhat congested.

I see numbers ranging from 18 mpg to 23 mpg. I think the average of 20-21 mpg is probably about right... Now, that in the light of today's skyrocketing gas prices, is not very frugal at all... No matter how you try to drive it frugally, it is going to be around 19-22 mpg. Let's factor out those folks who really do drive on empty freeways to work, where they get 25-28 mpg.

So, there... settle with that... and not try to see how much more mileage you can squeeze out of the RDX, but rather try to see how one can change their lifestyles, so that we don't use as much gas (mix in using some public transportation, cycling, driving it like you stole it etc...)

The engine was designed to provide a particular performance, at the expense of a particular gas mileage... You cannot make that engine squeeze out more mileage than what it was originally designed for. Law of thermodynamics...

Definitely the hybrid technology is looking attractive now and will probably consider it in a couple of years...

MMike1981

still dont see how empty freeway driving can equate to 25-28 mpg in this truck, just dont see it.

when someone asks me, hey what mileage does that get? my answer is 18 all around. anything more would be a lie, at least for me. but im not sitting around kidding myself that this truck gets 23+ its not even a thought that occurs in my head, when i see 20mpg im pretty much happy.

mav238

I totally agree... I average ~ 20 mpg when the city traffic is reasonably light.

When I was cruising at 60 mph on the freeway, I reset the MID, and it read for the next 15 mins while cruising at 60 mph, the mileage was ~ 27-28 mpg. But then occasionally, it will drop back down to 25 mpg. Thus if you can keep it constant at 60 mph, flat road, no hills to climb, you might be able to keep it at 28 mpg.

BUT, BUT... realistically, real life driving is not that ideal... so 20 mpg is the norm all RDX owners should be comfortable with... Otherwise, take out the turbo i-VTEC engine and drop in the Prius hybrid engine, and remove the AWD system, and replace it with the standard FWD chassis. Then you might get 26-28 mpg in city driving...

I hope people here are not paranoid anymore about who might be getting "FANTASTIC" exceptional gas mileage for some reason...

karrock

I'm over 11k for mileage right now, don't know the exact figure, it may be closer to 12k.

Also, just got back from another somewhat lengthy trip -- 273 miles of driving before I stopped for a low priced gas station (scary that I can call it that at $4.15 a gallon!) got me 28.1 mpg and so far this last trip reset puts me at 31 mpg with an average speed of 58 mph. That's the computer, but I've found that it's quite reliable and accurate.

MMike1981

31mpg....what lol

phoward_15

Yeah 31 seems way high...wow.

I just did another trip of 180 miles and got 21.3 mpg at an avg of 53mph. I only have 2,000 miles on my car but happy with what I'm getting.

karrock

Well, I just consider my MPG results a social experiment in a way... Noticing how many cars pass me and how quickly... Amazing how many people *don't* drive at the posted speed limit! I'd say about 97% of the cars on the road passed me and I passed maybe 0.5% all while doing the speed limit.

But primarily, I now know what the RDX *can* do in terms of gas mileage, even though that's not what it's designed for. Yes, I bought my RDX because it's a sporty kick in the pants that is (somewhat) light and tossable in turns and at speed and still deliver luxurious amenities, unlike most SUVs.

I'm not going to run around light-footing it all the time, but with the price at the pump being what it is, I'm certainly not going to stomp around on the accelerator at will either. I'll find a balance somewhere, probably about 10 over the highway limit (55 to 65 where I do most of my driving) and come out with mid 20's on the average MPG.

catnippants

For what it's worth - I've been impressed with how my mileage has continued to improve as my RDX ages. I'm at 23K miles now, and I bought it in Aug '06. At around 5K miles I was getting 19-20 mpg. I'm now averaging 22-23 mpg (23-24 on the trip computer), and I'm even less careful than I was a year ago. I generally mash the gas pedal and stop quickly. My ride to work is largely 40-50 mph, 22 miles, maybe 4 or 5 traffic lights. It's not really city driving, but I'm still impressed at the improvement.

Mike

karrock

Un-retouched. Just resized down to VGA res. Probably about 120 miles on the tank with noticeably less than a 1/4 burned. Current mileage on my RDX is 11,578.


By karrock, shot with NIKON D80 at 2008-06-02

mav238

Well... the gas prices is getting to me (seems like it is only going to keep going up, towards $2 per litre like in Europe)... and I have opted to garage the RDX during the week day, and use it only for the weekend/night excursions with the family. The public transport will be my main method of going to work.

No matter how we try to drive the vehicle optimally, it will never be a 30 mpg car in the regular city type driving... fact of the matter...

For those that do get 30 mpg, kudos to you... but you are probably hitting the freeway from your house and directly to your workplace... little to no city traffic...
Not realistic for most of us daily commuters to work...

Ahhh... on the positive side, the interior of the car (especially the driver's side) will look newer longer... and the engine/drivetrain will in principle last longer

dfvcl

Well, I am getting about on average about 24.2 MPG and about 395 to 402 miles per tank. Most of my commute is Hwy but somewhat congested due to the Dallas/Ft. W traffic. The overall gas mileage for the combine driving is 21.8 since the date of purchase. Yes, my driving speed has been put in check(between 60 -65 MPH) due to the skyrocketing gas prices.

XLR8R

With 410 miles range at 31.0 mpg you have about 13.2 gals left in the tank and have already traveled about 140 miles using about 4.5 gals, (provided you completely filled the tank).

Because the 31.0 mpg is remarkable (and trip B 20.9 is much more typical) I am wondering if these past 140 miles were from generally higher terrain to generally lower terrain, ie; mostly downhill?

I can see the RDX getting 30+ mpg at about 45 mph but more like 25 to 27 mpg at your average speed of 58 mph.

So what kind of road conditions yielded 31.0 mpg?

happywithmyrdx

Someone asked what 'city' driving was for me, it's driving in rush hour traffic just like anyone else, moving at 5 miles an hour.

Before doing any hypermiling tricks, I was averaging in the 22-23 MPG range. I just figured I would try to maximize sometimes to help. Since my last post, I've cranked up the tire pressure even higher to 50psi, and am using the 'pulse and glide' technique, coasting in neutral, along with turning the car off at stoplights [it turns out that anything more than 10 seconds at a light you getter better mileage by turning the car off versus idling], with a best of 34 MPG on a tank, this is mixed about 25% city, 75% 45mph or higher driving [but nothing above 65] and no air conditioning on.

Someone also mentioned that you 'can't make the engine more efficient'. Although that is true, you CAN make the driving style more efficient.

Before people think that this is all bs, take a look at some of the amazing mileage people are getting by using all the techniques, like driving without air conditioning or with all the windows closed, and coasting without the car even being on. It's remarkable.

I also did a drive from Texas to Florida , and using a car scanner, monitored what happens when using 89 octane vs 93 on the highway. For pure highway straight driving, no flooring it, gas mileage remained the same, and no knock was detected in the car. For gentle driving in town, the same was true. For anything involving a quick take off, or going up a hill, even though I could NOT hear any knocking, the computer was definitely detecting knock as the boost came on and was pulling timing. Several people have stated they are using 89 octane and had no problem. I guess this is true, and maybe the computer 'learns' over time that there is a problem, but it did not hold to be true in my car, it never 'learned', it always detected knock and then retarded the timing for a while. Just thought you guys might like to know. A blend of 50/50 89/93 octane also kept knock away from normal driving, I didn't really get into flooring it too many times, but I think that makes sense, since that would put it about 91 octane, which is all that is sold in certain parts of the country. I also noticed a strange thing, which was that I actually picked up mileage when using a gas with 10% ethanol. I'm not sure exactly why that is.

I'm averaging between 28-30 miles to the gallon overall on a tank with the hypermiling. Switching back to 'normal' driving and a 50/50 city/highway, and I sit at about 25mpg, probably a little better than average because of the higher tire pressure.

I thought you guys might like to hear about some of the testing I did.

Fishbulb

I'm one of the guys that runs 89 - its interesting as to your observations with the scanguage, thanks.

I'm curious though - when you refer to the car not "learning" that there is a problem, I'm a bit confused. The knock sensor coming into play IS the car detecting and correcting a problem. I'm curious as to what you were expecting... that it would throw a code, or something?

Anyway, nice writeup, it confirms my understanding of the behaviour of the car under mid-grade.

terdonal

If you are getting 11.7 L/100km that would 20.10 U.S. mpg or 24.14 Imp mpg.

While it is good to keep it in perspective for the U.S. folk we should also keep it in perspective for the Cdn folk as well.

mav238

At the rate the gas prices are rising, which seems to be up and up, trying to save money by using 89 gas, does not quite make much sense... To really see a significant savings, you should be filling half of the tank with water, and the other half with premium gas.

Just change your lifestyle to adapt to current world economy... drive less, plan your trips better, don't make unneccessary trips to the grocery stores, try to drive in off-peak hours (if possible), idle your car less in traffic... use the public transportation or cycle in to work...
Or buy a hybrid... best solution...

mav238

Have been taking the public transportation to work now for over a week, and I must say it feels weird initially and felt so good to get back in the RDX during the weekend... So far, driven once a week only... Will probably only fill up the RDX once every 2 months... Actually I am less stressed out now that I take the public transportation...

Fishbulb

Thanks for sharing. I was dying to know about the intricate details of your bus ride schedule.

karrock

Your math is good. On that leg of my trip, I made my gas stop near Harrisburg, PA and drove down 83 through York, 695 around Baltimore, down 95, around 495, and out the Dulles Toll Road to my destination.

I drive up and down 95, 83, 80, 15 and any number of other interconnecting major and not-so-major arteries through PA and NJ several times throughout the year. Not exactly what I'd call "mostly downhill" but plenty of alternating long climbing grades and downhills as well. Obviously not fuel inhaling killer mountain passes like you'd find closer to the west coast but not hundreds of miles of flat terrain either.

mav238

Well... my point was that there is really no sense in the continued debate about the fuel economy of the RDX... it is not a frugal thrifty car to maintain... 19-21 mpg in regular city/hwy mix driving. putting 89 gas into it is not going to save enough money over the year to really make a significant difference. To see a significant difference, should use 87 gas instead...

and my point is that, if folks are really hung up over the gas prices and the premium gas required by the RDX, then simply drive less of the RDX, and drive less aggressively as well...

Vash13

Let me add that if you are able to afford a luxury car. Gas should not be an issue.

XLR8R

I've driven this route a number of times as well, though not in the RDX.

The elevation where I-83 leaves Harrisburg is about 700'. It's about 433' in York and at Towson where it joins 695 is 302'. South of Baltimore, I-95 starts at 220' and joins 495 north of DC at 148'. That's some 110 highway miles descending 550'. Then around 495 and out 267, another 30 miles, you climb about 180' back up to 328' near Dulles Airport.

The red/green/blue path represents your descent profile, Harrrisburg to Herndon, left to right. I just picked a few data points so it doesn't follow the road, but gives a general elevation gradient. (There is a high point of 870' at the PA/MD border.)



Overall this trip is downhill, descending about 370', which I think may have been responsible for that excellent economy. I imagine a return trip would yield much lower mpg, 23-24 perhaps. Still, that's an encouraging report.

XLR8R

Here's a more accurate profile.

karrock

The 28.1 mpg I reported before the 31 was driving up north of Philly, almost to Allentown and back to VA, doing about 5 over the posted.

The 27.5 was strictly DC beltway and surrounding area driving plus a run or two towards and north past Baltimore.

And the recent low mark of 24.8 was driving a good hour north of Harrisburg, a jag across central PA into Philly and back the same route, but doing mostly 10 over posted and involving a couple traffic jams.

Where are you pulling those nifty elevation graphs from?

BleuM&M

He's pulling it from his Bongo, which he cleverly disguises as:

http://img135.imageshack.us/img135/2724/profileyi9.png

This reminds me of a graph from a TFR (terrain following radar) plot that was presented as evidence why pilots who flipped the TFR switch at low altitudes experienced alternating nausea and spinal compression.

You might also note the subtle inference that things go radically downhill once the PA/MD border is crossed.

XLR8R

Tsk-tsk. Another sad case of Bongo-envy.

Oogle Maps Leave it in "flat Earth" (counter intuitive, I know), center and zoom on your area, click points along your route, and then click "Draw profile". You can make a very specific profile.

The Peoples Republic of Maryland; all the charm of the North, all the efficiency of the South.

zalusky

Why does HP have to always increase with luxury.
Why can't we have luxury without the sports car!

XLR8R

Here for instance, is a profile of a drive through the Himalayas, though the program won't let me go up Everest and back down, so it's difficult to calculate the fuel economy.

BleuM&M

So far studies have shown this license plate motto causes excessive tailgating (small print) but they're working on it.

BleuM&M

Have you considered ZIL?

BleuM&M

Considering the terrain, maybe a graph in .02 mile increments might work.

zalusky

???

XLR8R

This is a ZIL, (Zavod Imeni Lihacheva) pride of the USSR. The man adjusting the wiper is "Uncle Joe", who was rumored to be BleuM&M's personal driver for a number of years.

BleuM&M

His driving style was actually the inspiration for Deathrace 2000.

MMike1981

people dont wana spend 40k and have a toyota corolla smoke them. luxury is almost always synonomous with higher out put, better handling machines.....you can get a nav/entertainment item in almost any car these days...hell even the focus has that sync garbage.

scudzuki

Personally, I bought the RDX for its performance.

The fuel economy is acceptable to me. I'm still surprised by some of the claims I see here. I am a consultant serving Chester, Delaware, and Montgomery Counties in suburban Philly. I see a couple of clients a day typically. If I really keep my foot out of it, the computer reports 18.5 MPG, and that is optomistic by 1 MPG as calculated at the pump. Yesterday I drove to Johnstown and back, and in approx 400 miles, returned 21.1 MPG (reported and actual) @ 75 MPH average on the PA tpk. That is my best yet.

Joe