Saintor

For the same commute with our Civic, I get EPA combined and I am not nice with it. I don't get even EPA city with my TLX.... I understand that it is only 10 deg F, but.... this is large pick-up level!!!

I was able to do EPA highway on a trip but I was certainly expecting better overall from this modern technology (9-sp. + DI +cyl. disactivation). I was expecting 25mpg, maybe 22.

accord1999

How long is your typical trip and its average speed? I've always found that the first couple of km after the car has been off for awhile to be quite poor in MPG. In city trips of 8+ km, I'll usually reach the expected city mileage in non-winter conditions. In the summer, beating the highway mileage is very easy.

NBP04TL4ME

You mention 10 deg F - do you have a remote start and/or are you warming up your TLX? If so, you are averaging in 0 MPG while the car is warming up. Just a thought as many folks forget about this.

Did you get better mileage previously in your TLX and something has changed or are simply comparing your new TLX to your Civic?

Help us help you with more details.

LaCostaRacer

You'll want to search the other 3G/4G forums for long threads on this subject. You have a 6 cylinder AWD car and 17MPG does not sound that bad in the middle of winter. I get 19MPG with a 26 MPH average speed in a much warmer climate , smaller motor and no AWD.

My guess is your average speed will be sub-25 MPH and that is the answer to your question. The 9-speed won't make any difference in your mileage for an urban commute since you won't be getting in the high gears. This issue is caused by long idle times and possibly running extra rich fuel until engine reaches normal operating temperature. Does cylinder deactivation even work when the car engine is cold and in sub-freezing temperatures?

AZuser

Didn't you get the TLX like less than 1 month ago? Engine hasn't even broken in yet. MPG will improve.

Is Civic new too? If not, it's getting EPA #s because engine has been broken in.

You could also check tire pressure.

CheeseyPoofs McNut

What's your avg speed? You can find it by scrolling through the mini display between the speedo and the tach.

sbillard

I get around 18-19 MPG in my city driving. All caused by my average speed. Somewhere close to 12 MPH! Cylinder deactivation happens only at highway speeds. Idle stop helps, but not if you start up right after it stops. I've learned to anticipate the wait and avoid idle stop when it will be short.

Comfy

BTW 17 mpg is the highway range for large pickups. Their real world in city short commute would be closer to 10-12. .

sbillard

Did an experiment on my last trip. Reset the A odometer before the trip. Watched the instantaneous MPG and average speed during the trip. Overall for the trip was 20 MPH and 21 MPG. The interesting thing was that (at least for this trip) the speed and MPG seemed to be almost in sync. At one early point speed was 49 MPH and MPG was 45.

audioxbliss

I average 20-25 mph during my commute and typically get ~19-20 mpg. When it rains my average speed plummets along with my mpg

Seriously, if environmentalists really want lower gas consumption, just get people to speed up :p

Rocketsfan

I've actually noticed this on most of my tanks. the 1:1 relationship holds until about 30 mph. Well, with the way I drive anyway...

youngTL

Even with low average speeds (traffic jams) I still get about 19 MPG even with letting it warm up. Short trips are terrible though. I find I have to go at least 5-8 km before getting good mileage in the winter because of warm-up time.

With proper warm up and a longer trip (usually my commute is about 21 km), I average a good 25 MPG.

And yes, VCM works when it's cold, but NOT while the engine is cold. The engine has to reach operating temperature before VCM works.

Auto-idle-stop works when the engine is warmed up too even if it's cold outside, but if it's very cold outside (-27 C for example - recently for me) it won't engage at all. When it's like -12 C outside I've had it engage then turn the engine back on like 10 seconds later. I just use brake pedal light pressure to modulate whether or not I want auto-idle-stop to engage (or just turn it off on my winter city drives).

Saintor

True my average speed is only 26mph. However I have to repeat that for the same commute, I get combined EPA with our Civic. 31mpg on the Civic and 17mpg on the TLX. If this continues, this will be my biggest disappointment with this car.

Saintor

... for the record, combined EPA for the TLX V6 is 25mpg.

*47% better than I expected.*

Saintor

I meant *worse*... lol!

youngTL

Saintor, it's a heavy car, much heavier than the Civic (over 500 lbs more), with a larger engine and the addition of an AWD drivetrain. Large, heavy cars with powerful engines always get poor mileage in stop-and-go situations than small cars.

Also, if you think that's bad, some Lexus IS350AWD owners were getting 12-15 MPG in similar conditions. If you really wanted fuel economy in city conditions, the I4 would have been the better choice. Or the Infiniti Q50 hybrid. Or the RLX Sport-Hybrid (if you could even find one).


I get fantastic gas mileage on the highway and decent in the city as posted above. But Edmonton doesn't have very tight stop-and-go traffic like Montreal does on a regular basis.

LaCostaRacer

You can't be comparing an AWD TLX to a FWD Civic that's 500lb lighter and has a motor almost 1/2 the TLX's size. It seems that perhaps the TLX is tracking very well if you account the displacement increase and the fact that you also have AWD.

If you really need AWD and demand economy, you should have bought a Suburu Legacy which ironically has a 2.5L motor and competes with the Civic 1.8L FWD very well: 30MPG .vs. 33 for the Civic for 2015 model year. The EPA combined for the TL is 25 so getting 17.x in the winter with possibly oxygenated fuel is really not that bad for a 26MPH average speed.

You should wait for summer and compare the two cars on a strict highway scenario and I bet you'll be pleasantly surprised- that's where the TLX will get closer to a Civic.

Saintor

You don't understand what I wrote; I compared their ability to meet EPA's combined mpg, which has been consistently the case with the Civic / same commute since 2012.

I am out of the MTL city and have no stop-and-go traffic to talk of. My commute is 2/3 highway!

LaCostaRacer

Something is not making sense. You claim 26MPH on your MID along with 17 MPG- that makes sense. Then you say you're on the highway for 2/3's of the time. So you must be in a lot of stop and go on the highway. How do you explain a 26MPH MID read on 2/3's highway with no stop and go traffic- that would be pretty hard to do on a normal highway where the speed is 55mph or higher.

If your commute is exactly the same with the Civic I would expect your Civic to not get the EPA mileage either. I don't recall seeing your Civic information, but I'll assume its a 2012 or older. A 1.8L Civic is rated for 28MPG city and you claim 31 which is impressive if you only get 17 with the TL in which EPA states 21MPG.

Do you verify your actual mileage with the MID? Perhaps something is off. I have found the MID to be very accurate with actual mileage and often on the conservative side where actual is a little higher. What I mean is my MID might read 19 MPG but the actual might be 19.9 or essentially 20. The most it has been off has been 2MPG in 10 years time and I blame that on a different gas station with possibly a bad pump calibration.

accord1999

For the pure highway section, you could reset Trip Meter B when you get on the highway and use it report the mileage and avg speed you're getting there.

I do it now and then and typically I see better than 6L/100 KM on that section with average speeds of 100-110 kph.

Saintor

I noticed that contradiction but I just reported what the computer stated. I don't have access to avg speed on the Civic, although I could try with my Scangauge II.

I do the same commute 4x 11km a day (2x in both ways)
2km to highway, at 40-65km/h (25-40mph)
1km on the ramp to get to speed
7km on highway
1km of city driving, maybe 2 lights and 1 stop

My Civic is manual (city 28 / highway 36 / combined 31). I get 7.6L/100km which equates 31mpgUS and it easily sticks there. The worst I saw is 9L/100km, which is is 0.4L/100km worse than its city 28mpgUS (8.6L/100km) rating - only +5%

Applying this same factor I could expect 20mpgUS for the TLX... but not 17!

Anyway I will let the engine run a few 1000kms but I saw no improvement recently. My first 2 tanks were on regular and I used premium since then. We'll see.

youngTL

A-ha! Now the necessary information comes out. I only ever use 91 octane fuel in my TLX.

Mr Hyde

Absolutely.

If you are using lower octane fuel, then your mpg, and power can be reduced due to timing being pulled. Those EPA figures are calculated using the recommended fuel grades.

oonowindoo

ask ur right foot.....

LaCostaRacer

The 3G TL will detune the engine so you won't get peak performance. In the one time I tried regular, I didn't notice a significant economy loss but performance was impacted a little. I suspect the TLX will do similar things but perhaps it will impact the MPG a little bit too. It's debatable why one would skimp on fuel with a new car in a decreasing oil price economy but that's for another thread.

I would really like to hear about MID calculated average .vs. actual and why a 11KM commute with 7KM of it freeway is so slow to cause a 26MPH average MPH. That's the reason the mileage is low.

I have a similar distance commute on city streets with lots of traffic lights and get that average speed @ 19MPG. I don't have AWD and have 300CC smaller engine. It seems like 17MPG is reasonable with the TLX in those similar conditions if it's too cold for that auto-stop-start to be useful. When I commuted to my previous job with a 3 mile jaunt on the freeway, I would get an extra 1-2MPG and near 20MPG with average speed of 29 MPH.

Saintor

I don't think so.

For the same commute, mileage is now much better at 11.3-11.5L/100km - 21mpgUS. I can live with that; at least I am now back in EPA range!

My previous 6-cyl. could use regular as premium was also recommended. It was probably a 3% detune on peak performance. In 85K miles I saw no significant difference on fuel consumption.

Acura seems to detune the timing much more aggressively if regular has is used. It is probably due to the high compression ratio 11.6:1 and that Acura must hate ethanol, present in most regular gas, but much less if any on most premium gas.

LaCostaRacer

^How do you calculate the MPG? Do you use the MID figure only or have you confirmed with a little math too? The MID is very accurate for me with my car but perhaps it's not accurate for you.

You don't see any point to the low 26MPH speed at all?

What about my first question in the quote above?

This means you will burn fuel for an hour and only go 26 miles. How much fuel do you think it takes to run for an hour and only going 26 miles? Having a 6 cylinder motor idling, accelerating up to 2,000+ rpm shift points, etc.

Ding ding ding:
Based on your data about 1.5 gallons. Just idling and going nowhere will consume about 1/3 gallon so imagine what traveling 26 miles does with stops and goes. Based on the 21 MPG city EPA estimate that's over a gallon but you're not going at a steady 26 MPH. You're going up to 35-40MPH and stopping for a few minutes or moments and stuff like that so that average is 26 MPH- that's a lot less efficient than simply running at 26 MPH.


Despite your opinion, the average speed data IS your issue. I have 10 years of driving experience to back that up if you want to press me on that- it's all at FuelEconomy.gov.


If you go to the FuelEconomy.gov web site and check the octane link, they state that economy can be adversely affected by using a low octane fuel. So maybe you'll see your MPG jump 1-2 just by switching to the fuel you should have always been using in the first place. That brings you to 19 MPG possibly and within 10% of the EPA's city rating which is 21 MPG.

With a 26MPH speed, you will never get 25 MPG so I would stop dreaming and complaining. I think you need a Honda Accord Hybrid if it this is a big issue.

Saintor

"Ding, ding, ding."

Now I have 28mph speed and it stays within 11.3-11.5L/100km, now more reasonable. Very same commute as with the Civic which gets EPA combined. I was also expecting close to EPA combined for the TLX and, aside of not using the recommended gas and being a very new, there is no obvious reason, no matter your smart-ass comments.

BEAR-AvHistory

Don't you remember the octane debates at the BMW sites? Results are always the same lower octane lower results.

FWIW back in the TL 3G days whatever the corresponding V6 Accord was Honda material talked about a 10BHP spread bottom grade to top grade.

LaCostaRacer

So changing octane increased your MPH? No- the increased speed improved your MPG which was my original point many posts ago.

Your car will improve with a full break in too. You might also want to check your tire pressure- that makes a difference. I run about 35PSI and not what is recommended for my car 32 PSI.

Are you going to confirm your MID with actual someday?

Saintor

So I heard and results are typically a 3% penalty or so on peak performance, not necessarily (but not always...) on fuel consumption. And this V6 is expected to do the same.

Case in evidence:

The Pilot uses the very same direct injected V6 with 11.5:1 compression ratio as in the TLX. It gets very good gas mileage for this class....*ON REGULAR*.

Specifications | The All-New 2016 Pilot | Honda Canada

And the only penalty seems to be: 10HP... or 3.4%.

The recent mileage improvement on my TLX coincides with warmer temperatures. I am ok with 11.3-11.5L/100km but hopefully I won't return to 14 as I saw in the first weeks!

LaCostaRacer

^ have you driven the Pilot in the exact commute to confirm your point your trying to make? We have a 2005 Pilot that we love and it's great on the highway getting about 23MPG going 80mph- it's in the city that it sucks and gets 15MPG.

If Canada uses oxygenated fuel, there's a high chance that some of your issues are caused by the blend of fuel- some people have claimed a 10% hit in fuel economy using MTBE fuel- that might account for 2-3MPG. In the US the fuel blend changes by March.

BEAR-AvHistory

Its a state by state thing IIRC some go past march. Its a given that Alcohol will reduce mileage. The weird thing is in a turbo it can increase horsepower.

My dynos were pretty close 60% 93 + 40% E85 VS 100% 100 octane.

youngTL

I'm also in Canada. I just did a highway trip where I got 5.9L/100km over 133 km. I verified the MID calculation and it was within 0.1L/100km. I have an SH-AWD V6. That is about 39 MPG for my American friends. I don't usually get that good though, since Red Deer to Edmonton is a small decrease in elevation overall. Going the other direction I tend to get around 6.4-6.8 L/100km (37 to 34.5 MPG). My car is now broken in with 4400km on the odo and I use full synthetic oil. Tire pressures are around 238-240 kPa while warmed up driving.

Saintor

Cold weather is back... and so is the 17mpgUS... on premium.

LaCostaRacer

That's pretty amazing that the MPG drops by 4 MPG or 20% because of cold weather (only) and no other factors- especially if a Civic gets EPA estimate under exact conditions. You would expect the Civic to drop its fuel efficiency about 20% as well if it was only the weather and no other factor. There's a reason- it just has not been elaborated.

Saintor

Not stop-and-go as discussed, but there must be some truth that short commutes affect much more large displacement engines than smaller ones.

Back on December 12th 2015, I would choose probably a TLX 2.4. Gas is dirty cheap but I am still pissed off to see my Acura get large pick-ups fuel economy while that little Civic continues to be an economizer for the same commute.

youngTL

I'm averaging 9.8L/100km in city commuting in Edmonton with my SH-AWD V6. I go up Terwillegar Drive, Whitemud Drive, 149th street, to 123 Ave for my commute if you want to look at a map. At rush hour, Terwillegar Drive and 149 st are clogged with traffic.

For the first ~2500-3000km I was getting 11.2-13.8 L/100km on the same commute. I swapped my engine oil with full synthetic around 4000 km on my odo and noticed some improvement after that.

For reference, large displacement engines are bad on gas for short commutes probably because they take longer to warm up. I also have a 2007 Acura TL-S 6MT and it gets almost exactly the same fuel economy as my TLX SH-AWD, except that it's worse on the highway than my TLX and slightly better in thick traffic. But on short commutes, it gets terrible fuel economy. My dad's Lexus ES350 also gets awful fuel economy on trips less than about 10 km.