Just bought a 2002 f150 S-crew. It has the LEV sticker on the window. Low Emission Vehicle? What changes did Ford make to achieve this
Brian

 

it was my understanding that they've been low emissions vehicles for a while.

 

What didn't they change to achieve this?

 

It was the move to 5w20 that increased mpg's slightly.

 

MPG has nothing to do with the LEV rating. The Expidition had a LEV rating when it was brought out. If you look at the trucks exhaust system you should notice there is four catalytic converters. This is how they get the LEV rating. The LEV rating is based on Carbon Monoxide(CO) and Nitrogen Monoxide(NO). The converters basically scrub these gases into less harmful ones like Carbon Dioxide.

 

Sask-Harley,

I would disagree, everything has to do with the LEV rating. I'm sure Ford streamlined this across the board in 97 with the modular engines if not earlier with certain models. Great advances have been made in emission controls in modern vehicles, and they can be divided into three general types: 1) engine modifications, 2) external cleaning systems, and 3) fuel vapor controls. What you are referring to is #2) external cleaning systems.

Regarding engine modifications (and someone can correct me if I'm wrong) but I believe two significant changes have been made including 1) combustion chamber shape and 2) lower compression ratios. Older head designs had complex combustion chamber shapes with areas that almost touched the piston head when the piston was TDC. This mixed the air and fuel more thorougly, producing more power with less detonation. However, this also caused unburned fuel to condense and cling to the sides of the chamber. Modern chambers have simple shapes and small surface areas to reduce fuel condensation. Also, modern engines have lower compression ratios, which lowers the temperature of the combustion process, making it less likely oxygen and nitrogen will combine into oxides of nitrogen.

In short, I doubt Ford did anything different for the LEV in 2002 than they did in 2001, but overall one thing that Ford did to get the LEV is create an engine with less torque and horsepower than it could have otherwise....

 

And along came Superchip. LEV and fun to drive!

 

ACTUALLY a higher compression engine is more efficient and probably lower emissions, the trick is to get a high compression to run on 87 to 93 octane. the trucks today have higher compression (9 to 1) then the trucks of the 1980's and middle to late 1970's (8 to 1). but you are right , in any case cylinder heads are where its at. they are the key to power and efficientcy. this is probably why you see very little about porting and hot rodding the modular head.

 

You can also add in the fact that the engines are operating at higher temperatures than in the past.