I've recently purchased a 1997 RL in perfect condition. Well, except for the fact that I've been getting somewhere in the 11-13 mpg range. A good bit is city driving, but that seems awfully low from what I've read. What problems could be causing this? Spark plugs or the fact that my brother (previous owner) ran the car on regular unleaded for 8-9 years. I tried premium and it didn't improve the mileage. He kept exceptional care of the car and it looks and drives new. Any suggestions?

 

I also have a 97 RL, there are several things that can affect your mileage.
1. Air filter
2. Dirty o2 Sensor
3. Driving aggressive.
4. Depends if most of your driving is city compared to highway, regardless the speed your car still burn's gas while idling at the light.
5. Full tires add less drag on your car, so low ones burn more gas.

I also recommend you get it checked at the dealership, they did a recall on my car for free, something to do with starter, ignition and the catalyst. I do 50% city 50% highway and honestly the 97 is not a champion in fuel efficiency, I average about 16-17mpg, it's an older car with older technology, newer cars have more accurate gas mileage printed due to new laws. I've never seen great mileage from this car to be honest, 11-13 is a bit low thou, I would get it checked.

 

Having used regular gas for all those years didn't help either. Higher octane fuel improves power and fuel economy on premium vehicle due partly to that the higher the octane the more resistant the fuel to igniting.

 

Something is definitely wrong. 11 - 13 mpg? I drove my 96 RL for over 200,000 miles (got it with 48k and it died at 251k) over 8 years. 80% highway driving; usually at 70 - 80 MPH. I got 21 - 22 mpg on every fillup. I used premium for 3 years and switched to regular for the last 5 years with no change.

 

I have a 1997 Rl and I consistantly get 20 mpg in a mixed driving between city and highway

 

Your car should not chug gas like an Escalade.

Something's definitely up. I get 20-23 depending on how much hwy I use.

 

Try to get the minor tune up first, install new sparks, fuel filter, injector cleaner... Let see if that improve or not.

 

Get your ERG vavle check too. That was part of the problem with mines. Its probably clogged.

 

First post...our '97 RL with 224,000 miles on the odo gets 20-22 mpg on every tank. On trips we get 23 mpg with the air on and closer to 25 with the air off. Out of California gas sometimes we get in the high 25's. Cruise control helps and the a/c on, in the intermittent mode. Running the a/c in full mode has the a/c compressor working full time, and I don't recommend that. If you don't have a check engine light on, the bulb might be burned out. I would take the car in for a recall check, and have the dealership check the car over with the diagnostic checker. It will print out a report of what codes are stored in the computer and help pinpoint the source of poor mileage. You might get back a monster when you resolve the problems, as this car really wants to fly.
EGR valve, mine was repaired twice under a factory recall. I hear it is buried down between the heads.
If the fuel filter is plugging up, you will use more fuel to make the car go as its starving for fuel.

 

How do you know if your car is covered under the factory recall? Are they still honoring the recalls still to this day?

Do they charge you to run a diagnostic on it?

Thank you in advance.

 

Yea, I really wanted to know about this too. I've read thread a long time ago about Acura, they will do the emission system for free. is this right? Does any one have any ideas about this?