The Wiff mistakenly filled up our T-5a with 87 Octane. Any suggestios on an octane booster to remedy
                      this ill, or would it be OK to just leave be and re-fill with the good stuff on the next tank?
                      Thanks!!
                      Cheers,
                      Tim
                      --
                      86' 240DL; 98 s70t5a

                      I, personally who always use Premium fuel would not add anything...one tank of lower octane will not
                      do anything bad to your car...
                      Yannis
                      --
                      '01 V70 T5 M, Red/Graph L, Sunroof, Rear Spoiler, Cold Weather, 4CD Surr.Sound, 17" Tethys Alloys

                      No emergency. Drive on. Lovely Wife does the same thing when she fills the 245Ti and that thing
                      doesn't have a knock sensor!!! I just don't floor it. SWMBO is always correct, because it's cheaper.
                      Your car can compensate and in fact you may get a little cleaning action....
                      --
                      Paul S.

                      Tim, you might find out the Wiff has done you more good than harm. You might find out that premium
                      fuels are a marketing ploy to get you to pay for what you may not need. Your turbo probably LIKES a
                      little more octane, but it does NOT require it. Look in your owners' manual. It says minimum is 87 and
                      they recommend 92 (or something like that - I don't have the manual handy) for turbos. The key word is
                      RECOMMEND. So, rest easy and see how the car behaves. If you don't notice much difference, your
                      Wiff has just found some extra cash for you. Lower octane fuels have fewer additives and ignite easier,
                      this is why your timing needs to be retarded when using them to prevent pre-ignition (explosion before
                      spark). This is what that pinging is. If you don't hear the pinging of the engine (and you should not as
                      your car has a way to detect pinging and adjust its ignition timing accordingly to eliminate it) you are not
                      harming it. If the performance decrease bothers you put higher octane in next time. So, no emergency -
                      keep on trucking. My car is N/A and I always use 87 octane. I have for many years now done that with
                      all my cars and they ran well into triple digit mileage with perfectly running engines. The important thing is
                      to keep that valve train clean by driving the car the way it likes to be driven - fast (RPM, I mean).
                      Cheers.
                      --
                      Vladimir. Base 1998 S70 5-speed manual.

                      Tim,
                      Harm ? - No !, Damage ? - No ! Like all of the other people stated, there is no harm using 87 octane,
                      BUT you will notice a big difference when you pressed on the accelerator. I don't know where you're
                      living, but if it has hills, you will notice the difference. I know you didn't purposely
                      filled it with 87 octane, but if I was you, I would drained out the entire tank, and re-filled it with a
                      higher-octane or whichever one you would normally used with your T-5.

                      My girlfriend has a Jeep Grand Cherokee Limited with the big 5.9L engine.
                      She insisted that 87 octane is good enough for her. Result - I refused to drive her Jeep when we go out.
                      That Jeep just wouldn't go ! I tried "pulling" with a Sunfire GT coupe, and it lost ! ~ Imagine that ! Hell !
                      it even lost to my friend's 1997 Volvo 850 T5 sedan. I formally had a Dodge Durango SLT with the
                      same 5.9L engine as her's, but she keep wondering why mine is more powerful. From day one, I have
                      been using either 91 or 94 octane with all of my cars, and yes !, including my NA S70.

                      Well ... this is just my opinion & experience with using 87 octane. That is YOUR Volvo and it is your
                      choice !

                      Good Luck !

                      Kenny                       1998 Volvo S70 GLE                       2001 Mazda Protege ES " GT " ~ Won in a local contest !
                      ( On Order [ 1 month ]: 2001 Audi A6 " AllRoad " Quattro )

                      What about using an Octane booster? Any recommendations?

                      Tim,

                      Your car will retard timing and limit boost to prevent any problems
                      associated with the lower octane. Chances are it won't even do that
                      in day-to-day driving during the winter (when the air temp is cool).

                      I would not add anything to the fuel (except the occasional fuel
                      injector cleaner every 10K miles but you probably don't even need that
                      if you use premium or mid-grade fuels since they have added detergents).

                      And ignore the drain the tank advice -- too dangerous for the
                      given problem. (Especially since it is not even a problem.)

                      By the way, I've run all 3 grades in my T5. Normally use premium
                      but have had no problems with the other grades.
                      --
                      Ray Niblett 95 855 GLT / 98 S70 T5M

                      Thanks for all the advice! I'm not panicking anymore!
                      Cheers,
                      Tim
                      --
                      86' 240DL; 98 s70t5a