Truth behind MPG

Ok I had this conversation with chris earlier and here are my real-world findings on increasing fuel economy. Keep in mind I have a 4 banger so results may or may not be relevant to you. I started at 18.9 mpg with tires re-inflated to my specs, and driving intelligently.

Things that helped:

• Driving style is huge. Slow acceration helps a little but not significantly. Mainly shifting and (as another member said, not sure who) driving like the breaks don't work
• Switched engine to Mobil 1 0W-20 synthetic added 1.5-2 mpg
• At 30 K maintenance, I seafoamed, cleaned the throttle body and switch all fluids over to synthetic. This added 2-2.5 mph
• Tire pressure. Keeping them properly inflated gave me better milage than the dealers "soft ride" inflation. I had no numbers at this point so I can't say how much it helped.
• Ethanol-free gas got my final MPG from 22.9 to 24.6

Things that didn't help (but did not hurt it)

• Removing secondary air filter and the AFE Pro Dry S air filter. This gave me .5 mpg tops.
• Headers (only had them on for 3 tanks so it may need longer to get solid data), but since then my mpg has been about the same.

 

I'd add one clarification:

For folks who do a lot of suburban/outer city driving like me slow acceleration is the main point of savings. For highway driving, not so much. I tested this over 2 tanks... if I accelerate about 25% faster than my normal my MPG goes down 1.5-2.

And +1 on the ethanol thing... instant -10% in gas mileage.

 

I agree completely. I find accelerating smartly in city helps a lot, while getting up to speed promptly on a highway does not matter