Answer: If your vehicle is equipped with a catalytic converter in the exhaust system, the leaded fuel will contaminate the catalytic converter and render it useless. We would not recommend even one tank of unleaded gas with a catalytic converter. You may want to consider keeping a full 5-gallon gasoline can available for emergencies.

Question: 2004 Honda Accord, miles 38,000 I drove to Minnesota from Canada yesterday, and filled up with "Off Road" gas, which I was unfamiliar with but thought it was just a higher end gas, the lady then got upset and told me I had put diesel fuel instead of gasoline into my car, I had it pushed out of the way, and there it sits as we were unable to siphon out the gas. I will go back tomorrow and try to find a garage to help me, do you have any advice, guidelines or precautions in dealing with this. Apparently this is the forth time it happened at that station this week.

Answer: Siphon out as much diesel fuel as possible and the refill it with gasoline. Your car may smoke somewhat until the tank is used up but rest easy; the diesel fuel will not harm your car's engine.

Question: 2002 Ford F-150 mileage: 65,000. Very strong fuel odor in the passenger compartment. I located a Technical Service Bulletin for this problem. I called a dealership and they would not give me any details of the TSB except that I should bring it in for them to fix. I don't need them to do it; I just want the details so I can do it myself. Where can I find this info, and do you know the cause. Once I have this, I can move forward! Outside the car the odor only seems to be in the engine compartment, not anywhere near the gas tank. I have checked all over the engine compartment for wet or oil spots, and have found none.

Answer: The bulletin you refer to explains that there may be a missing sealer between the fuel filler opening upper flange and the fuel filler base assembly. The recommend fix is to reseal the gaps in the fuel filler opening.

Answer: Some cars have knock sensors that adjust timing for different grades of fuel and some do not. On cars equipped with a knock sensor and where the manufacturer recommends 91 octane, a lower octane fuel can be tried because the knock sensor will adjust the timing for the lower grade. However, performance and mileage will suffer. Now to your specific car, it most certainly will suffer if you use 87-octane fuel.

Question: 2000 Lincoln LS V-6 mileage: NEW. I just purchased the 2000 Lincoln LS V-6 engine. The owner's manual says use Premium Gas with 91 octane but the dealer says use regular unleaded. Who should I believe?

Answer: In a way, the manual is right and so is the dealer. Your car is equipped with a knock sensor that adjusts the timing to the octane of fuel that is being used. The higher the octane, the better the performance you will get out of your engine.

Question: 1999 Ford Mustang GT mileage: 45,000.  Is it ok to use high octane gas in my car? I was told not to use more than 87 octane because higher than that can burn some gaskets.  I figured a high performance car should get high-octane gas.  Please help!

Answer: Using gasoline with a higher octane than is required by the manufacturer should not harm your engine.  However, it may make an unnecessary dent in your bank account with no added performance advantage.

Question: 1998 Ford F-250 mileage: 100,000.  Hey there,  recently I went to my mechanic because I was concerned about why my truck was eating so much gas.  I went from filling my gas tank up about every 2-3 days to filling up once per day (not even driving a lot).   He looked at my vehicle for a little bit, gunned the heck out of the engine and he said that it had to do with my catalytic converters.   After he was done gunning my engine and giving me the great news, my truck had A LOT less power and was backfiring tremendously (similar signs of other people who have asked you questions).

Answer: We do not know what could be causing your knocking.  Perhaps it is an exhaust leak but normally a knocking sound is not what is heard.  As for the lack of power, the first thing to check is the cylinder compression.  If this checks out okay, install a fuel pressure gauge and check the fuel pressure, as it may be low causing a lean condition.

Question: 1999 Mazda Miata mileage: 88,000.  Having a problem fueling my Miata.  As I am pumping gas, the pump will constantly shut off, as it normally does when nearly full, but throughout the entire filling up of the tank.  Earlier problem last year resolved after "prolong" fuel additive, but then restarted a couple months back.  Don't have any more prolong, but other additives aren't helping.  What's up, and what can I do about it?  Thanks

Answer: From what you have described, we think you may have a vent hose that is kinked or somehow restricted or the main fill pipe is restricted.  You may want to try a different gasoline station, as the problem may be as simple as the gas nozzle on the gas pump.

Question: 2003 Mazda 6 mileage: 33,000.  With the rise in gas prices and the manufacturer recommending premium gas.... I was wondering.... Does the use of regular gas (87 vs. 92) harm or do anything to my engine?  If I should mix the gas should I alternate tanks or fill 50/50?  If no harm is done, why do they recommend premium?  Thanks.

Answer: The car manufacturer recommends 92 octane for your car because of the compression and performance of your engine.  Running a lower octane may work although engine performance will suffer and you may experience some pinging.  Your car is equipped with a knock sensor that may adjust the timing to eliminate the pinging.

Question: 1999 Volvo 850 turbo mileage: 80,000.  If a fuel injected car runs out of gas, will the engine be damaged?

Answer: Running out of gas should not damage the engine, however, if one were to keep trying to start the engine with no gas, the fuel pump may be damaged.

Question: 2002 Pontiac Aztec 76,000.  I put motor oil in my gas tank because I thought it was gas line anti-freeze.  I only put like a cup or so in.  I drove it to school today and there were no problems.  Then later I filled it up with gas.  Is there anything I should do?  Will it be ok?

Answer:   Motor oil in the gas tank will cause no harm; in fact, a slight amount is beneficial to the motor.

Question: 2001 Ford Focus mileage: 25,000.  I recently purchased my first fuel injected car "unleaded fuel" and I have heard horror stories about clogged injectors making cars run badly and even damaging engines.  I spoke to my brother in law "who has had several fuel injected cars" and asked him which fuel additives he has used to prevent such problems.  He said don't worry about it just fill up on Premium unleaded every 3rd tank or so and everything will be OK because Premium is a cleaner fuel and it will keep my injectors clean.  He has had no injector problems in 12 years.  What is your advise on this?

Answer: ;  Normally if you purchase major brand gasoline the injector cleaners are in all grades.  The only difference between premium unleaded and regular unleaded is the octane rating.  If your car does not require premium, buying it serves no purpose.

Question: 1998 Jeep Cherokee mileage: 110,000.  My car is experiencing terrible gas mileage and has a strong odor of unburned fuel.  Upon opening the hood at idle I can see gas literally dripping from the injectors.  A friend said it is probably the O-rings and they need replaced.  Is this a fairly easy repair if you have a Chilton manual?

Answer:   Leaking gasoline is an extreme fire danger.  If you are unfamiliar with the O-ring repairs, have it done professionally.

Question: 2001 VW Passat mileage: 43,900.  Since I bought 3 yrs ago runs best with least amount of gas in the tank tune ups, wire sets, you name it  - can tell it runs smoother by the way it shifts so smoothly, the stable tach, etc.  When I fill it up it doesn't immediately return to rougher running but overnight or so and it does. Pressure lines to carbon canister or is a gas cap or?   Really runs great with 4 to 6 gallons or less left in the tank.  Have replaced fuel filter too.  The mystery here is what does the quantity of fuel have to do with the engine performance.

 Answer:  You are on the right track; the problem is probably related to the carbon canister.  Raw fuel instead of vapor may be in that system.  Start with gas cap to be sure it is the right one for your car.  Check hoses to and from carbon canister that they are connected properly also check vacuum valves.

Question: 2002 Ford Taurus mileage: 54,000.  My mechanic is having problems solving a rough idle problem and a hesitation in acceleration at approximately 35 mph.  The car idles fine in neutral, but in drive, the idle is very rough.  After a major tune-up (plugs, wires, distributor cap, rotor, thermostat, fuel filter) and the replacement of some vacuum lines, checking the TPS the problem still exists. Also, what is the recommended octane for the 3.0 liter V-6, I am hearing a slight pinging. Also does anyone know a good Ford mechanic near Century City (Los Angeles) CA?

Answer:  89 Octane fuel should run okay in your car.  Your car is equipped with a computer controlled engine management system.  An independent auto service center can scan your computer for fault or error codes.  The information should pinpoint the malfunctioning components.   Sorry, we do not know any mechanics in your area.

Question: 1999 Dodge Stealth twin turbo mileage: 38,600.  This car calls for premium fuel.  Why?   What does premium fuel do that regular will not?  What would happen if regular were put in this car?  What type of reliability can I expect from this car?

Answer:  Your engine in your car is a high performance engine.  Premium fuel reduces pre-ignition and detonation (pinging) in your engine.  If you use regular gas performance, would suffer and cause possible engine damage.  With proper care and maintenance, it should be a reliable car.