99+ intake manifold hurt my mileage

[tysonxj]

It is true.

 

[dhreeves]

whats the difference

 

[*89Laredo*]

Winter gas has more volatile compounds in it to make it evaporate/atomize/combust more readily in cold weather. This also decreases the power/efficiency it produces...

 

[yossarian19]

I think it also has additives to account for damper conditions, but I could be wrong there. Ethanol, wasn't it?
Either way - winter gas burns like somebody peed in the tank.

 

[Blaine B.]

Ethanol is a nasty thing. Gasoline without any ethanol would be more efficient. The more ethanol mixed in, the less efficient (and less MPG) it gets.

 

[kujito]

You now are running winter gas (switched last month) and a drop of about that much isn't that uncommon on winter gas.

What do you mean by 'winter gas'? If you mean the +10% ethanol blend, most gas stations here (Denver at least) have that year round from what I've noticed.

I read an article in the newspaper (remember those things?) a while back about how we get a special 'summer' blend.

The city usually suffers from a temp. inversion (cooler air at surface than aloft, surface air doesn't rise) which traps pollutants close to the ground. That's where our nice 'brown cloud' comes from, as well as some extra EPA attention. I also noticed that the ethanol stickers on the pumps are up year-round now.

 

[hubs97xj]

The mix, according to some folks, varies by season, location, and brand. I don't believe the ethanol content is the only variable. I haven't paid much attention since gas came back down from $4+, but when they were building the ethanol plant here, the fuel types and efficiencies were a hot topic. It's probably available info if you dig a bit.

 

[Blaine B.]

Right, 10% mix is usually year round unfortunately, but in the winter there are different additives and I believe more ethanol as well. Although there are many excuses it is probably a scam, you have to fill up more and put more money in the gas companys' pockets in the winter. Who wouldn't make up an excuse as to why the gas has to do this to you?

 

[winkosmosis]

So if you switch from a 99+ to earlier manifold, you can gain gas mileage??

 

[POLAR_JEEP_04]

So if you switch from a 99+ to earlier manifold, you can gain gas mileage??

it all depends on what head you have.