herbert said:Thats some greaT FUEL MILAGE.. i SEEM TO AVERAGE AROUND 14 MPG IN MINE.. WHAT SPEEDS R U DRIVING AND R U USING UNLEAD OR SUPER? THANKS HERB
Our 99 QD gets from a low of 16 to the best so far 21.07, and I drive whatever the posted speed limit is, but never over that. I accelerate and stop smoothly and back off the gas on hills (we live in the Ozarks). You can tell by the sound of the engine when it strains, and it generally doesn't even slow down if you back off a bit. Always keep your tires up to proper inflation. We drove from Missouri to Maryland fully loaded (fuel and water) using premium only, and my worst in the mountains of Pennsylvania was a solid 18mpg, and we got 21 in Ohio, Indiana, and Illinois. On the return trip the same route, I used only Regular gas (87 octane with ethanol) got 1 mpg less and I'm sure a bit less power. But for the cost, regular was the better option, being premium was 70 cents per gallon more, and it never pinged in the mountains on regular. I always use Stabil in the gas regardless, for the sake of the generator. This spring I intend to put a shutoff valve on the generator fuel line and simply run it dry when stopping it, then I won't have to buy the Stabil. The sticker says 16-22 mpg, but we've never seen 22 with it yet. I'm running 50 lbs air in the tires, check it every time I fill up.
Most all German motors want premium gas, and it might help some vehicles to run premium, but it will run just as clean on regular. However, your own driving habits may get you better mileage with premium, you just have to try it both ways. Keep in mind the weight of the Rialta, though. I believe our 99 has a 10:1 compression ratio, which is high, and probably should have premium to keep it from pinging for most drivers. But if you make sure it doesn't ping (that destroys piston ring lands and can damage heads), you will do fine with regular. My personal recommendation as a lifetime mechanic would be to use premium in hilly country or mountains to avoid preignition. Regular is fine on the flatlands if you don't accelerate hard. And smooth driving is easier on your transmission, too, not to mention your gas mileage.