Mazda 6 Engine Problems

E10 FUEL usually has a higher octane rating than fuel without ethanol, and the E10 on the market has a minimum octane rating of 94 RON, which is suitable for your car. You can use regular unleaded, which has an octane rating of 91, but you will lose performance and your fuel consumption will increase. There is no affect on warranty.

BUY the RX8. Rotary engines are typically heavier on fuel than a four-cylinder engine, and your V8 comparison is probably correct. They have also been a little heavier on oil than a piston engine, but that's not a problem. The RX8 is a high-performance sports car and needs oils that protect it against hard driving.

The recommended fuel for the Mazda6 is 95, while the oil companies claim E10 has a minimum of 94. Your car would most likely run fine on E10, but I wouldn't expect it to perform as well or give the same economy as it would on PULP.

IT DOESN'T make sense for the oil level to fluctuate if you haven't started the engine or moved the car. Perhaps you are somehow pushing the dipstick further down when you recheck the level. If you're worried about it I would have the oil drained from the engine and replaced by the correct amount of new oil as specified by Mazda, then see what level is shown on the dipstick. Remember to account for the oil in the filter when you do it.

MANY cars have chains instead of belts, and carmakers seem to be returning to chains after many years during which they preferred belts. Belts were introduced because they cost less than chains. They are also quieter than a chain, which can be quite noisy as it wears. As to why it isn't mentioned in road test reports, I can only say it is a little too technical for most readers. They are more interested in how a car performs when put to the test. It is the sort of detail the buyer should check before settling on a new car.

In a sense you've already answered your own question. You have used 91 octane without a problem. The Mazda 6 will cope with the lower octane but will run at its best on the fuel with the higher number.