mdb007

Having only had this base 12 for 2 months I was really excited the first month getting about 26-27mpg with a 80/20 hwy/city. Then it dropped to 25-26 but the temps were falling so it was running richer. Filled up the other day and now hovering at around 22.5-23.1 mpg. Outside air is 22˚. Do you all get similar mileage? I have been using Costco gas for the past 7-8 years and running the premium.

Thanks

horseshoez

iTrader: (2)

Interesting, my 3G 2006 6MT typically averages 28/29 mpg summer with an 80/20 mox, and more like 26/27 in the winter, even when the OAT is down in the 20°.

losiglow

iTrader: (1)

I seemed to see a more pronounced difference in fuel economy in the winter with my 3G but for some reason I haven't noticed any difference in the 4G. I haven't kept track though. Just observations. I've always averaged about 25-26mpg 50/50 city/highway and closer to 29/30 when 90% highway (like roadtrips). That's been regardless of temperature.

dv-

'12 Base TL, 26mpg for most of the winter on Costco Premium E10.

I was getting 28-29 most of the summer, same gas and commute.

mdb007

Thanks , yeah seems really weird to drop down 2-4mpg even with colder weather and driving the same route every day. I'm thinking about getting a tank of non ethanol gas to see if that makes a difference. I was really excited with that initial mpg because the maxima sucked with the cvt! 22mpg and with a bad o2 sensor dropped to 19.

losiglow

iTrader: (1)

I tried EtOH free a few times but never noticed a difference in either performance or mileage.

Anicra

I dont know I do these 250 mile runs I can pull 27.0 to 28.2 MPG with ethanol prem and 29.5 to 32.5 MPG on Non Oxy. We are talking 95 pct on cruise, set 9 to 10 over with Radar detector on. I had a crazy fall run where I was at 35.5mpg and I hit freaking fog for like 50 miles. I would have broke my 32.7 MPG record, bummer.

mdb007

Thanks for your input, trying to figure out what is going on, it bounced back to 25.3 but the temp was around 25˚. Now around 11˚ and getting 24.3 and I know they run richer in cold. I may clean the MAF sensor and see if that changes anything. I am pretty consistent with my driving so not sure why the 4mpg swing but our weather has been all over the place this winter. I will try the non ethanol gas in spring to see if i notice a change in mpg/power. And last week when I filled up computer said 23.5 but I calculated 25.3, the Acura computer seems pretty much spot on from what I have seen the past 2 months since I got the car.

horseshoez

iTrader: (2)

A few comments:

• You are way over-thinking this situation.
• I do not believe your car has a MAF sensor, instead I believe it has a MAP sensor (similar acronym, very different functionality to measure the intake charge weight); regardless, cleaning it will not provide any benefit. In fact, as often as not, folks cause other issues when messing with it; long story short, leave it alone.
• You cannot get an accurate read on fuel economy from the Miles/Gallons calculation from any one tank of fuel. Fuel pumps click off at different points which may be over a gallon different from one fill-up to another.

mdb007

Yes I am probably over thinking it . However I fill up at the same place 90% of the time and always squeeze of a a few clicks as i know every pump is different so within a couple of tenths should be fairly accurate. And this is based on about 12 fill ups, but with the temp swings the past 3 weeks can't count on consistency. And I just looked it up it is a MAF.

Thanks

placer

My mileage always drops in the winter. no matter what car I am driving. It is normal, at least in the frozen north. Cold air, cold fuel, longer warm ups. I usually average (with my TL) about 26-27 in the summer. Now it is more like 23-24. More city driving than freeway these days.

mdb007

Yeah guess I thought it would drop by 2 winter not 3 to 4. Still a lot better than my Maxima which sucked summer and winter 19-20mpg ugh.

placer

After several days of way below zero temps here, I took a look at the on-board MPG screen and it is showing 21.0 MPG on this tank. The lowest I have seen. It is usually fairly accurate compared to my calculated (actual) numbers.

horseshoez

iTrader: (2)

Makes sense.

Regarding OBC versus good old fashion miles divided by gallons; what I typically do when I get a new car is to log the first 20 tanks of fuel and calculate the MPG for those tanks and compare it to the OBC, this gives me the standard error for the OBC (so far every car I've had over the last 20+ years, has ranged from +1% to +4% optimistic), I can then apply the error correction to the OBC number and come up with a highly accurate MPG figure for each tank.

mdb007

Horseshoez, Thats a good method for calculating the error rate. So far on about 9 tanks most have been spot on with OBC but one was better by hand than computer. So how do you figure the error rate then?

horseshoez

iTrader: (2)

There are two ways, the easy way, and the hard way:

• The easy way: Reset your OBC when you fill up, and then don't reset it for ten tanks; divide the total miles by the total gallons, and then divide that result by the OBC's running average. This will give your your error rate.
• The hard way: Create a fairly elaborate spreadsheet which calculates a weighted average from your per-tank OBC to derive what your overall OBC's running average would have been had you use the "easy" method, and then follow the rest of the instructions from above.