Canadian here and cold - hugging an ice cube for warmth.

I'm wondering if anyone can give me an idea on why my R/T gets such crappy mileage - I'm estimating around 20 mpg and that kinda sucks. Our '94 Intrepid with the 3.3 got over 30 mpg and I don't have shares in any oil wells or gas companies. Changed the air filter to a K & N, not much changed.

Like the car - not the mileage.

Thanks for any replies.

I had a 1995 LHS with the 3.5. It consistently delivered 28 MPG on trips, and, was probably a bit heavier than your car. I suggest you check and see if your overdrive and lock-up clutch are working properly. Typical symptom is excessively high engine RPM at interstate speeds. Had this problem with my 2001 Sebring. It drank gas. Had the dealer check it because tach was indicating about 3000 rpm at 70 mph.
A Chrysler tech checked the tranny control module and found that 4th gear and the lock-up clutch were not engaging at all. He fixed the module and my mileage jumped to 30 - 31 mpg at interstate speeds. This is with the 2.7L V6. Hope this helps.

Regards:
Oldengineer

My R/T is running about 2000 RPM at about 60 mph. It seems like the motor is working extra hard. To help increase the mileage would it be a good idea to go to a taller tire - sticker on car says MINIMUM size of 225, would going to a 245 cause me any major grief other than the speedo is out of calibration a little??

Thanks for any replies.

what motor does your R/T have in it? i have a 3.5L and i get around 28-35 mpg on the highway u could possible check your plugs fuel filter air filter plug wires and your pcv valve

I have a 2002 Intrepid SE and at about 60 MPH, it's taching at 2000 RPM. The reason why your intrepid runs high RPM is a combination of two things. 1) Your car weighs 3600 pounds. Yes the 3.5 V6 is a very strong motor, suffieciently power enough to move your car from point a to point be, but it still can have its toll on overall fuel economy. The second factor is the final drive gear ratio for the differential. On intrepids, the ratio is 3.89 to 1. In other words, for every 3.89 turns the engine turns, the drive wheels turn one revolution. That's a high number but it's needed to propel such a large car like the intrepid down the road. Last piece of advice that you can try is when you are cruising down the road at 60 MPH, see if it shifts into all 4 gears and then while at 60, lightly put your foot down; not too far, just enough to raise your speed slightly. If the RPM jumps then your torque converter clutch is not locking up. If not, the converter is fine. I don't highly recommend it, but STP makes a great fuel system cleaner. Try that as a last resort and see what goes.

Give the car a tuneup (air filter, spark plugs, tire pressure, etc). This will ensure the car is operating at its peak.

Finally, I have had great success with Valvoline Syntec Oil Addative (Silver Bottle sells for about $4 at Autozone). This synthetic addative has increased the gas mileage by about 2-3 MPG on just about every car I've tried it on. The addative package really helps to reduce friction (PAO synthetic and moly). For a few bucks, give it a shot.

Good Luck!

The car got new plugs, new K & N air filter, and new PCV. I am using Schaefer's synthetic oil and I usually add Schaefer's Neutra as a gas additive for longer trips. The tires are checked at least once a month. (Fuel filter is in the gas tank - not changed, and the car doesn't have any spark plug wires.)

New problem has also come to surface within the last couple of weeks, at least Chrysler has a TSB on it. Just a major job to change the plastic washers under the exhaust springs to correct the start-up noises -> major tappet noise - like no or low oil pressure. I guess while I'm in there changing the rusty plug tubes I can go the extra step to do the valve washers.

Thanks for all the great information I've received. It's great to get such valuable information from such informed people.

GREAT WEB SITE!!!!!!!!!!!!!!!!!!!!

Canadian here and cold - hugging an ice cube for warmth.

I'm wondering if anyone can give me an idea on why my R/T gets such crappy mileage - I'm estimating around 20 mpg and that kinda sucks. Our '94 Intrepid with the 3.3 got over 30 mpg and I don't have shares in any oil wells or gas companies. Changed the air filter to a K & N, not much changed.

Like the car - not the mileage.

Thanks for any replies.

Just been reading some forums and I noticed yours, reason being I have a 2001 Chrysler Intrepid R/T [sweet car] I don't drive it much but my wife does [imagine that!] I 've checked my gas mileage making trips back and forth to Ottawa [yes I'm a Canuck too] I would get usually about 25 - 26 Mpg which I thought wasn't too bad for a car with 250 HP. Sounds like you may have a minor problem that is sucking up some fuel , possibly O2 sensor ?