I was at the toyota dealership today ordering my scion xB and i couldn't decide on a few things. I was wondering if the cold air intake effects the gas mileage and if so how much. and just how much extra hp do you get from it???

 

The cold air intake from spec's I have seen only gives you an extra 5-15hp. The 5-15hp is a range I came up with after seeing various different reports in HP gain. In my opinion, such a small gain is not worth it. As for gas mileage, I do not know if it effects it at all, but I was watching Horsepower TV on Spike TV and they said a cold air intake makes the engine perform better, but I dont know if that means an improvement in gas mileage or what.

 

A cold air intake helps horsepower because it provides a) cooler, denser air and b) less restriction. The engine pulls in air when the throttle is opened. At WOT (Wide Open Throttle) the only real restriction for air getting into the chambers is the air filter. Getting a better flowing air filter allows air to get in easier and improve VE (volumetric efficiency, the amount of air that actually gets into the cylinder vs. the cylinder's actual volume). Since you don't normally drive at WOT all the time (hopefully), you're not so worried about that. Under normal driving conditions (partial throttle) there is a vacuum in the intake manifold because the throttle is restricting the amount of air that gets into the engine. The pistons pull air in but the restriction doesn't allow the full amount of air to get in. At this point the air filter should ideally not be a restriction because there is not very much airflow. So CAI's do not help mileage much.

 

... the $300+ CAI offered by the dealship for these Scions, as after I pressed for solid answers, it will only truly produce about 1 or 2 HP increase.

I appears from what I was told and read as well, you only really will see an "increase" on the high end of the revs, and may actually see a DECREASE in performance on the lower to mid level revs!!

You would do better off with a simple K&N filter replacement for $50 or less for that kind of performance change, and I have read too often about how the filter head on some of these CAIs break in short order.

I think my local Scion dealer was truthful in telling me, if I want more horsepower than what these Scions have to offer, go buy another car with higher ratings. You can only push and squeeze so much out of these little engines.

 

You won't feel any difference in power from any cold air intake on this type of engine until you are waaaaayyyyy up in the rpm range. Even then, some say they can feel it and others say they can't. You will, however, get a nice, sporty tone to your engine under throttle. You will acheive better fuel economy, but these gains are minimal at best. You'd be hard pressed to find someone who has reputable documentation showing even a 2 mpg increase over time with a cold air intake.

I'm not saying the cold air intake isn't worth it, but I think most people expect too much from it.....

 

I've notice a marginal increase in throttle response and a sportier engine note (AEM CAI). Only you can decide if it's wortth it or not. It's not going to win any races, truth be told the difference with any CAI, especially on an engine this size is probably just barely measureable. Its more of a little add-on for fun than a legitamate performance upgrade. If you want to add measureable performance to your car that you can feel, you chose the wrong car. Get a new Mustang or something with some cubes to work with if you want actual power from your mods. These cars are just for playing around with.

 

I'd be surprised if there is any difference at all. The Scion AEM intake is a pretty close replica of the stock intake, except executed in shiny aluminum with an oiled gauze filter hung on the end. They had to do this to make sure that the oiled gauze filter didn't kill the AFM and to get it past the CARB. To my knowledge, Scion hasn't published any power specifications at all for this part. the only numbers I have seen are verbal "estimates" given to the press and others.

 

The AEM intake isn't anything like the stock plastic box and plastic hoses with rough edges and ridges to disrupt airflow. It's a totally different animal xcept for putting the intake part in the same general area--- thats because that where the air is coolest. That said, you're still only looking at perhaps 4-5 hp at the high end of the tach. Barely enough to notice.