Falling Gas Mileage - Anybody Else?

[usulsuspct]

Date	          PPG	   GAL	    MPT	  ODO	   Total	MPG
6/26/2005	$2.36	21.581	318	377	$50.91	  14.74
7/4/2005	$2.23	20.346	310.4	687	$45.35	  15.26
7/5/2005	$2.34	4.774	76.7	764	$11.17	   16.07
7/18/2005	$2.36	20.978	323	1086	$49.49	  15.40
7/24/2005	$2.44	20.032	333.4	1420	$48.86	 16.64
8/5/2005	$2.42	18.555	275.2	1695	$44.88	  14.83
8/25/2005	$2.66	20.336	285.1	1980	$54.07	 14.02
9/4/2005	$3.44	20.085	345	2325	$69.07	  17.18
9/20/2005	$3.00	19.871	282	2607	$59.59	  14.19
10/12/2005	$2.90	19.917	253.2	2861	$57.74	 12.71
10/19/2005	$2.70	7.242	90.5	2951	$19.55	  12.50

Recently I have noticed a drop off in my gas mileage, has anybody noticed this? I keep track of my gas purchases from my first tank. For the most part these entries are all city miles (except for the 16 / 17 mpg entries.) Recently it seems like I have trouble keeping the mileage above 14. My driving habits havent changed any. I am not complaining per se, just concerned that something is wrong, and looking for some feedback from some other owners.

[1bigtexastitan]

That's weird, my Titan did exactly the opposite of yours. I now have 5090 miles and the mpg is getting better (15.7) all of which are intown miles. I have not been out of town yet. I have been taking it easy during the first 5000 miles to break it in. Have you changed the octane of fuel? I use the middle grade (88 octane). I have also changed the oil twice. The next one will be at 6000 miles. All of this is of course my personal opinion which I have observed. Hope this helps.

[shawnwat4]

my gas mileage falls in the same parameters. My city driving gets roughly 12.8 to maybe 14 on a good tank. highway i'm around 15.5. i have always been told your gas mileage should improve slightly over time as the engine breaks in. i wouldn't worry too much. its bound to fluctuate some due to uncontrollable variables, i would think it'll creep back up to mid 13's, low 14's eventually. just a thought

[meckman]

Has it been getting colder in NY? You might want to check your tire pressure. I was getting slightly worst gas mileage these last couple of weeks. I checked my tire pressure and it was down about 5 lbs all around from where I normally keep them. I aired them up and I'm getting better gas mileage now.

[usulsuspct]

Originally Posted by meckman

Has it been getting colder in NY? You might want to check your tire pressure. I was getting slightly worst gas mileage these last couple of weeks. I checked my tire pressure and it was down about 5 lbs all around from where I normally keep them. I aired them up and I'm getting better gas mileage now.

It has been getting colder, that is a good idea about the tire pressure. I will check it tonight. I just did my first oil change we shall see if that helps with the mileage (switched to M1 EP 5w30.)

[DeeDubya]

I've got a little over 3000 on mine now and still getting around 12.5. It does, however, seem to be running a little stronger than when new. I'm sure that's because of the cooler weather.
I could tell you more if I had stayed at a Holiday Inn Express last night!

[abmobil]

If it is geting colder they may have switched the fuel in your area to the winter blend which will also hurt fuel economy.

[JamesB]

tire pressure and your ready for an oil change.

I saw mine slip from 15.5 city/highway (light foot the truck) down to 12.5. changed the oil and this tank look slike about 15.

[usulsuspct]

Originally Posted by JamesB

tire pressure and your ready for an oil change.

I saw mine slip from 15.5 city/highway (light foot the truck) down to 12.5. changed the oil and this tank look slike about 15.

I will check tire pressure, but I just changed the oil (see above.) I didnt realize they changed the gas during winter months.

[buzzkillwill]

I know all about the cold and tire pressure. The first 'chilly' morning here, my tire sensor went off! So, I'd say my tires were a little low...DOH!!

As for the gas, it could be the winter mix starting, I think that's what its called.

The other thing cold(er) weather brings, longer warm-up times. I know that alone wouldn't account for gas mileage change you've seen, but add that, plus tire pressure, PLUS cold weather mix, and you might have the answer...

BTW-Mine did the opposite too-it started low, around 10.5 and went up to 15+...

[phlydude]

Originally Posted by abmobil

If it is geting colder they may have switched the fuel in your area to the winter blend which will also hurt fuel economy.

That's what I think it is too. Mine has gone down as well and I think that they have started to add the MBTE to the gas in the Northeast.

[rarjar]

May be pretty obvious, but have you checked your air filter?

[baseballfanz]

Mine seems to fall into that same category (milage wise it look like your chart). One thing that puzzle me is when new and I was getting 14 mpg avg. I had to fill up once every 6 days, now with the lower mpg I fill up every 7 days (same driving habit, same route to work and home, basically same routine). I use to get 300 miles easy on a tank but now about 275 - 280 the most. Don't know if it's related but notice the lower MPG after my first oil changed to synthetic.

[Helinut1970]

I wish I could get your lowest gas milage! Right now im lucky to get 11.5 miles per gal. Of course I tow off and on. But still the last time I got over 12.5 miles to the gal I had to drive like the rest of the old farts down here and I cant have that. I figured it wasnt worth the savings to drive so slow. I would rather lose a mile per gal and have some fun doing it.

[milleniamarv]

Along with the change in wintertime gas formulation, might add into the equation of colder air being more dense thereby taking more power (and more gas) to push our large frontal area at speed. Granted the engine will produce more power with denser air but my feeling is aerodynamic drag subtracts more in efficiency than this increase in power adds.