2008 Avalon - Lower MPG than expected

[volantis]

I bought a 2008 Limited in December. I've recently been getting lower gas mileage than I expect based on others' comments. Any feedback on what could be causing it? Yesterday I drove from TN to MO. I started w/ 3/4 tank and got 23.5 MPG cruising around 75 MPH w/ laser cruise control. The next tank got 27.9 according to the display, which usually reads 1.5 MPG high, while cruising around 73 MPH.

Is this normal or should I be getting better? I've thought it could be tires, tire pressure, gas, or maybe oil (haven't gotten to my first change yet, but it is CPO so I assume it has the correct synthetic in it).

Any thoughts on what I can do to get better mileage, assuming that's not normal?

[arabianobsession]

1) If you drive 70 instead of 75 mph, you will see in increase in mileage
2) Double check tire pressure. Don't assume it was set correctly at the dealership.
3) 2008 Avalon did not come with synthetic oil originally, it's 5w-30 dino oil. You can, however, switch to synthetic if you like.
4) It's winter. I know you're from TN, but it's still colder there than most cars would like. You will always see a drop in mileage when it's colder outside. My 4 cyl. Camry went from a 28 mpg average in summer to 21 mpg in winter. (Granted, it's colder here, I know.)

[boosted-fc3s]

I get over 30 in summer with summer gas. I routinely get 23-26 in winter. EPA recently approved E15 gas for 2008 and newer cars too, which has more ethanol, if that's in your area, that would cause worse mileage as well.

[TheUltimateBohab]

winter makes a difference but a huge difference (I’ve noticed it in every car I’ve ever driven) is where you get gas ill get gas at a shell or Mobil and get around 30-35 depending on the temp above or below freezing makes the difference, but if I get gas at the Phillips 66 or the BP in my town I’ll get 22 at best regardless of the temp. I use premium btw

[tfelton]

I hadn't focused on temperature as being a factor, however, I checked my mpg records and found about a 4 mpg difference from winter to summer (28 vs 24). On long trips in the Summer I will get in the low 30s. This has been true for the years I've had the car which I bought in February of 2008. The car now has 59,000+ miles on it. As far as maintenance goes I use 35 lbs in the tires and Mobil 1 0W-30 oil. I understand 15% corn in the gas has been approved but I haven't seen it yet at the pump. I hope it takes a long time coming.

[pmesfun]

Try some fuel injector cleaner.
On the 07, it averages around 22-23 during winter and about 25-27 in the summer. City driving. On trips with my dad driving its gets around 31-33.

[TrailDust]

Speed is certainly your biggest mileage killer. My 2002 XL gets 32 MPG at 65 MPH, and at 70 MPH drops to 29 MPG. You have to decide which is more important, mileage or speed.

[volantis]

Originally Posted by TrailDust

Speed is certainly your biggest mileage killer. My 2002 XL gets 32 MPG at 65 MPH, and at 70 MPH drops to 29 MPG. You have to decide which is more important, mileage or speed.

This was my first thought, but I routinely see people claiming 75-80 MPH with over 30 MPG. I'll check the air in the tires and maybe try some new gas.

I saw someone else using premium. Just curious why. The car doesn't call for it and I doubt the compression ratio is very high, so it seems like it would hurt mileage or stay the same, but not help.

[tfelton]

Another factor I feel greatly influences mpg is wind. We drive out west a lot and when you're on I-40, I-70, or I-80 for a whole day (especially I-80 in Wyoming) wind makes a big difference. I also feel that if you're driving a long distance in a day (we normally do 1,000+ miles the first day of a long trip) not driving at break-neck speed makes for a more enjoyable and relaxed drive.

I tried premium and found no mpg advantage at all.

[Mike Murrell]

Ignore the MPG display on the dash....it is all over the place.

My wifes '06 Avalon has never gotten anywhere close to what was advertised on the window sticker.

My observation is cars get approx. 15% less mpg than what the mfg puts on the window sticker.

If you are getting what the mfg advertised.....good for you.

[eldernerd]

Interesting to see other's experience which are very similar to what I've see in mileage figures. Wind...I'll get 3 to 4 MPG more driving east that west. Winter drops my mileage from 33-34 to 30-31 in an 08 Limited at speeds of 70 to 72 MPH. I run the tires at 34 pounds but may drop that to 32 if there's ice or snowpack anticipated in the area.

[TrailDust]

Originally Posted by volantis

This was my first thought, but I routinely see people claiming 75-80 MPH with over 30 MPG.

I call on anyone claiming over 30 MPG at those speeds. Don't believe them.

[tfelton]

i did a trip to Dallas not long ago: first tank was 366.8 miles using 11.924 gallons for 30.76 mpg; second tank was 292.0 miles using 9.695 gallons for 30.1 mpg. Mileage was interstate 30 plus driving in Dallas. These are actual numbers, not from the dash.

[TrailDust]

What was your average speed?

[tfelton]

I-30 is 70 mph so I do 70 to 75.