Hey guys, so my 4 cyl 2011 TSX had been averaging about 28 mpg combined. All of sudden it is down to 24. I haven't changed octane (using 91), tires are inflated to 33 cold. Wheel alignment feels right on. I don't drive the car too hard. I have no idea why the drop. Any thoughts ?.

Are there any computer adjustments that can be done ?.

Thank God gas is cheap these days !.

 

Winter will lower your MPG. The colder temps will have your engine working harder to get to its regular operating temperatures. Notice how when you start the car, the RPMs are hovering maybe a few hundred RPM higher than usual? This is likely the cause.

Also, if you're using an autostarter or just simply leave the car on to "warm up", it'll lower your MPG as well.

 

27.6 MPG on last tank on my wagon. freeway its seeing 80-85mph. 6 onramps (elevated) per day, two huge hills. 85% highway, rest city. I use premium.

 

I don't really warm up the car. 30 seconds, max and drive away slowly.

 

There are multiple reasons why temps affect gas mileage.

Denser air and not running the AC contribute to higher mpg, but higher rolling resistance (unless you've adjusted your tire pressures to compensate for the cold) and winter blend gas take a toll on mpg. You also tend to idle longer and take your car on shorter trips with cold weather.

 

OP seems to have corrected tire pressure. Are you running winter tires? Winter tire compound will typically yield lower MPG than summers/all-seasons as well.

What ceb said basically.

 

Winter gas blend . It will change towards the end of march

 

The tires are the original tires that came with the vehicle. I guess I'll settle for winter blend as the answer ?. Never happened before though......

 

One other thing you can look at, as this has happened to me.

When was the last time the brakes were checked? I have had the guide pins dry out and my calipers hang up which caused the pads to drag on the rotors a bit more than normal. I too saw a decrease in mpg, and brake pad life.

It wasn't really noticeable until I changed the pads, rotors and sanded and lubed up the guide pins. Once I got it all back together, I really saw the difference and mpg was back up to where it should be.

It might be worth looking into.

 

This might be worth a look, as I just had my brakes replaced about 3k miles back.

 

I think TSX mpg is good...

for mine, I drive in los angeles areas with traffic so... about 80% city driving and 20% is freeway... and that comes out to be about 23.6

 

Same.. I'm roughly that MPG too. Except it's gotten a bit worse ever since I got a Hondata FlashPro and the RV6 PCD

 

IF I got 23 I would sell my TSX. A car cant be slow and bad on gas. Hah
!

 

The TSX gets great fuel economy on the highway and combined. When you're doing 80% city like dwk and I are, there isn't much you can expect. 23 is decent in that regard.

 

Get about 22 mpg in city and suburban driving and 28-32 mpg at 70-75 on the highway. Most highway driving is PA, WV VA and NC where it is hilly.

 

My 2012 TSX is not slow. I rarely have to "floor it" and it has plenty of power for most driving situations. I don't know why everyone is so fixated on 0-60 times and acceleration.

 

I average 22 MPG 95% city driving... this is spirited driving with a V6

 

So it turned out I was driving around with a thermostat that was stuck open. I only finally noticed when it got really cold and we had snow / ice. Noticed the heat was slow to come, kept an eye on the gauge, and suddenly I realized what was going on. Took to dealer, they replaced under warranty, and now the avg MPG is up 2 miles (only 1/2 tank sample size but it looks much better).

 

winter gas is actually different from summer gas.

 

that's funny.. i usually get 28 in the summer and 24 in the winter with my v6. stop driving like a lunatic?

(i actually drive mostly on the highway)

 

Runnin 29.8 according to tsx computer. That was average over like 6000 miles. Live in ct so what is a city?
Whats your guys take on the accuracy of the cars computed mileage?

 

TSX calculations are off by 5-10% in my experience.

It's generally more accurate with mostly highway driving.

 

No idea but I'm fighting with my computer right now lol. It keeps flipping between 11.0 L/100km and 10.9 (~21 MPG). I do mostly city, but it used to be ~9.8 L/100km (~24 MPG) in the summer.

I also use the autostarter or just idle longer these days cuz it's too cold to even use the steering wheel , which negatively affects your MPG since you're at 0% efficiency with your burning fuel.

 

Computer showed range of 580miles. Realistically got 461 miles, before she took 17 gallons.

27.11 MPG in the wagon, this tank.

 

Wow. I'm at a consistent 19.x mpg. And it doesn't matter if 91 or 87(?) octane so I guess that's nice.

 

I use premium which is 91 here, and not 93, sadly.

Car sees 80-90 miles a day, more on call days.

Car sees 85mph most of the time.

Lots of hills/onramps.

If I drove it 65mph, and on flat roads, I bet I would see 30+.

So dumping my hybrid for this, I am losing about 13mpg but not having to go to the station every 2 days.