38.6 MPG highway Golden Egg! WTF?!?!?

[orange4boy]

Thank you Ecomodders!

I went from my last record of 26mpg highway to 38.6, 37, 36.9. When I started coming here I was getting 15-20 mpg. This is a 3500 lb mini van.

Grille block, 2" air dam and new rear oxy sensor (replaced main earlier)

City is still at around 20mpg. Anyone care to guess why my city and highway are so different?

So thrilled!

[azraelswrd]

Be more aggressive in efficient city driving by aiming for your gear optimums and sticking to them. Make sure the tires are aired up. Anticipate potential stops or idles from lights or signs like your life depended on it (because your MPG life will rise and fall with every full stop and gas gorging acceleration from a dead stop).

Neutral coasting to a stop can save a little gas. Engine off at a light will save more gas.

[Daox]

To really up city mileage you just really need to use the brakes as little as possible. Use coasting as much as possible, and use in gear deceleration if you need to slow down faster than just coasting. Its not easy, especially in an automatic, but those are petty much the biggies. Other things to do are engine off at stop lights, and accelerating agressivley, but keeping rpms low.

BTW, that is amazing mileage in a minivan. Great job!

[NeilBlanchard]

Hi,

It might be better to downshift when you are slowing down -- use this along with the brakes to gain "infinite" MPG while slowing down. Coasting in neutral is better for carrying speed as long as possible. When you need to stop, downshifting to use the engine to slow down the vehicle is better.

When you are waiting at traffic lights that you are familiar with, and/or where you can see the lights for the other roads -- you can shut the engine off, and only start it right before you need to move.

[orange4boy]

I'm doing most of the things suggested in terms of driving habits and I am getting far above EPA. I get 20-23 city, EPA is 15city. I'm thinking that it's sheer mass that is my problem in city driving, and the van is heavy (3550 curb). Once I get going on the highway, It's mostly drag and rolling resistance and the Previa is a very aero vehicle even compared to many sedans. That's my guess as to why the spread between city and highway.