Increased my mpg by 2mpg on my MazdaSpeed3

[azasadny]

I switched my engine oil to AMSOIL 5W30 and changed the manual tranny fluid to AMSOIL 75/90 on my 2007 MazdaSpeed3 (now has 5000 miles on it) and I have increased my gas mileage by 2mpg, which isn't too shabby.

I'm driving the same route to/from work, driving the same "style" and all else is the same, so the only thing that changed is the engine oil and gearbox fluid. The fluids are also 100% synthetic and have an extended life versus dino oil.

I'm not affiliated with AMSOIL in any way, just a satisfied customer.

[kaisen]

Your car might also be breaking in. But Amsoil (and other good synthetics) certainly help.

[speedracing944]

I vote for broken in.

Speedy

[azasadny]

Could be the "break-in", but the mpg increase was noted over the past 200 miles. I'll keep monitoring the mileage (OBD-II scanner) and see if the mileage is consistent, but so far it has been.

[kach22i]

Just wait 30 years, it will be leaking all out of the seals and ruin your clutch disk too.