Ever since the air temp has gotten consistently below 40F I have been UNABLE to achieve much more than 17mpg city and 20mpg highway.

This is down considerably from my 19mpg city and 22-23mpg HW mileage when the weather was warm. Warmer than 50F.

I have never seen this kind of drop in any of my other cars...

 

My MID is actually showing higher numbers; however, I've only put about 40 miles on this tank so far.

 

I think that the problem may be the fuel and not the temperature. Turbo engines actually run much better with cold air. Remember that during winter the put additives in the gas that may affect your fuel economy.

 

That might be true. I've been using Get-Go Gas recently because I have lots of Fuel discounts.

After this tank I'll run a couple SHELL tanks and see if that makes a difference.

I too thought the cold air would actually help the turbo in the RDX.

 

Is not the brand, is the blend that they make for the winter time....I think that your results will be just about the same going anywhere.....
People should expect decreased mileage during winter time....

 

Is everybody still putting in Premium? I find that after a couple of months, it doesn't bother me anymore. Plus prices have subsided a little bit. MPG b on the MID which I have not touched since purchase has risen to 19.7
Not bad for a big CUV that is incredibly fast.

 

My MID is about 1 to 2 mpg better than actual calculated mpg.

 

what do you mean still? you should always.

 

I get about 16.5 in winter. There are some slight changes to winter blend gas, but it shouldn't be that significant. Most of it is due to the less efficient driving - a lot more warm up time, slower traffic, more idling etc.

 

This is going to be my 4th winter with my RDX - and I consistently get 19-20 in the winter (mixed, mostly rural driving), and 22-23 in the summer.

Mike

 

ALWAYS put premium gas in a turbo vehicle!

 

Saabs actually run just fine with regular or premium....their system automatically adjust the spark to run on either one.

 

The $5 a week I could save by not using premium gas is not worth it to me. All gas is expensive these days. The difference in cost to use premium is actually pretty minor.

 

I use about 1 tank a week. So it's only about 3-4 dollars more a week. I pump "Premium" because I have a Premium car

 

I agree that premium gas is highly recommended for driveability of the vehicle. Why save on a few dollars when your car feels sluggish and just no more fun to drive? If we have to pay double for using premium gas, that would be a different case, I would probably stay away from cars requiring that.

 

If by drivability you mean to prevent detonation of your engine I agree fully.

 

Driveability includes engine output due to timing being retarded from knock on regular gas.

 

I've been using premium fuel ever since I bought my first new car back in 1987. My RDX is no exception. Premium all the way! As another post stated, with today's gas prices it doesn't make a whole heck of difference $ wise premium vs. regular. I feel better knowing the car's engine will perform the best it can.

If you can't and/or don't want to spend for premium fuel then why drive a car that recommends it? Rather, go buy a fuel efficient Honda Civic, etc..

 

By driveability, I mean the engine ECU compensating for the lower octane, by adjusting timing via the knock sensors. This will decrease the engine performance.

 

This is surprising, but good. I always get the opposite results.

 

Maybe this is because additives are added to the fuel, but lower temperatures usually lead to better mileage, and better performance.

 

i've been mixing it up, getting 8 gallons of 89 (mid-grade), then topping the rest 8+ gallons with premium, which is 93 octane here, since that will average up to recommended minimum of 91. It only saves 1.50 or so which I probably piss away every day by forgetting to turn on some lights at home, but the psychological effect makes me happy
Also when you turn on the heat using the auto AC mode (I just leave it on auto and adjust the temp), it will also turn on the AC compressor so your windows wont fog up, which will also decrease mileage.
I've also noticed less mpg, but that's normal because I've been leaving the engine on while cleaning the snow off the car. Leave your trip computer on average fuel economy and you'll see how bad idling reduces your average.

 

Mileage is likely to be lower in the colder weather because the air is more dense. Since the vehicle senses Air/Fuel ratio, when the air is denser it will have to inject more fuel to achieve the proper ratio.

 

My mileage also drops slightly in the cold. I wonder if perhaps slightly lower tire pressure (due to dense air) if one hasn't readjusted also reduces the mpg a bit.

 

Why do you guys think it's called a Cold Air Intake? Why do you think that it is installed in car to improve performance and perhaps fuel consumption? Guys, cold temperature has nothing to do with the increased fuel consumption, it's the gasoline blend in the winter time (that's what I believe)

Also, I believe that the density of the air is a function of the barometric pressure, not temperature. If it is true that the air is colder in higher elevations, the added consumption is due to the altitude, not the temperature of the air.

EDIT: I understand that warm temperature excites the molecules of the air, therefore for a given mass of air, they occupy a bigger volume, then d=(m/v) will be smaller than what it would be in cold air........

 

For the second time, most of it is due to the less efficient driving - a lot more warm up time, slower traffic, more idling etc.

The fuel does contain a bit more light ends to aid in cold weather starting. I took a course on refining and the instructor said it might have a 0.5 mpg effect or so.

 

Bought a 2010 RDX FWD in Nov. Just took it on a 1400 mile roundtrip to VA from FL. On the trip up in warm weather the MID indicated a mpg of 29.6. However, after driving in the bitter cold for 2 weeks and in the trip back to FL the MID indicated a 26.6 mpg.

 

A FWD RDX justs takes all the fun out of the SH-AWD...even if you are getting much better mpgs...

 

Meh....most people will be fine without it...If I didn't need it I would totally buy the FWD....then again, If I didn't need it I would not have an SUV