2004 T&C 3.3L only getting 22 MPG on Highway!!

[hassanbigboss]

Hey guys I have a 2004 Town and Country with a 3.3 L engine which has about 49000 miles on it. My daily commute is about 95% highway and my average speed is about 75-80mph. I have done the mpg test by measuring the gas used every time I fill my tank. I noticed that I only get 22-23mpg on the highway. Is this normal because to me that is kind of low. I use Mobil 1 5w-30 for my oil and I also have a K&N AIR FILTER installed. Please help me with this because as everyone knows gas prices are going to go up during this summer which is going to kill my wallet.

[neon_rt]

That sounds about right. The EPA 26 Hwy estimate is based on a test loop that runs at about 55mph with some surges to 59mph.
So 22mpg at 75 to 80mph sounds OK.
I traveled from Salem to LA (900) miles last year (in one day) and averaged 21mpg. Most of the trip was at 75mph some spots I hit 95mph.

[hassanbigboss]

Thanks Neon. I do not know why I was expecting better mileage then this but considering the fact that the car weighs 4300 pounds this is still okay. Thanks for the reply.

[vipergg]

As the previous poster said it because you are going 80 mph . It makes a big difference going that fast , if you drop it to like 70 mph it will go up to like 25 -26 mpg . Took ours on a 1400 mile trip , all highway and it never got less than 25 mpg , usually doing 70-72 mph.

[RIP]

96 GC 3.8 ltr gets me 22-24 mpg at 70-75 mph from 90 miles north of LA to San Diego.

[HeadlessHorseman]

I've got a 1996 GC LE with a 3.8L motor and 229,000 meticulously maintained miles on it. The "sweet spot" speed on the highway for my vehicle is 61mph. I was able to calculate best real-time gas mileage with the overhead computer. At this speed, set with cruise control, I easily get 26mpg.

[neon_rt]

Horseman,
Interesting 61mph observation. I have the overhead display in my '00 GC 3.8l and I have experimented with different speeds vs gas mileage since I got it. I too have observed the 61mph "sweet spot". If you do a search of the Forums, you will see that I have mentioned it elsewhere. The readout most often shows 28 mpg at 61. If I do mostly highway driving, the average per tank comes in at 25 - 25.5mpg. If my wife drives the whole time, it gets only 19.5-20mpg.
I recently removed the OEM muffler and replaced it with a 'glass pack' or sorts. It is a oval muffler with a continuous pipe the runs un-interupted diagonaly through the muffler. I left the factory resonator in the tailpipe.
So far, it seems my wife is getting 1 more MPG than she used to. I have not had a chance to drive out a whole tank myself. 1 mpg is about 5%, 5% savings translates to 15 cents per gallon at the pump. It cost $160 parts and labor for the muffler so it will take a little over 21,000 miles to break even, if the 5% observed increase is actual.