No arm wrestle and, everyone has an opin, but if K&N air filters really
offered up a 2mpg inc., they would be in every car, oem, imo.

The mfg'ers would chase that extra 2 mpg avg. like they chase
vendors for cost cuts.
GL,mD

Not necessarily...increasing air flow is good, but in doing so, the K&N filter will allow more dirt/debris into your engine in the process. The minor mpg gain is not worth the risk of engine damage.

Got any specific information to back that up? Not saying it is inaccurate, I've just never seen a spec sheet stating more particles were coming through.

You are right!

My parents have gone through Mercedes and Porsche. I like both of those, but I don't think I would ever really want one. I think you'd actually have to pay me to drive a C55 or any C-class in general.
The S4 just doesn't have anything special about it. I like how when you see a 4.6/4.8, you know it's one of those because of the exterior features. Although the RS4 is a beast, I test drove one of those a month ago or so.
At this point I'm just searching around for opinions and thoughts, still not positive about really trying to sell my car. But it would be fun to get into a car, that's the only thing that's keeping me thinking about selling...

RS4?!

Big dough and 20mpg, with a tail wind, downhill.

I thought your current mpg was a prob.?

So did I!!

Honda\Acura are in high demand. I sold my Pilot within a week with no discount in price.

MatzoBallsX5 - owning a car is a very personal decision. No two people will agree on it. In your case you have decided that gas is a factor. Okay, done deal, sell the X and get yourself a fuel efficient coupe or sedan. If you get a used car you may even end up with money in your pocket!

Now to answer your questions...It is generally better to NOT sell to a dealer because he needs to make money off your car so he can't give you market value. You need to sell it yourself. First, put it in autotrader and get the deal that shows it in the local magazine and online. Do your research to determine the market value. Let that sit on autotrader for 2 to 3 weeks. If you get no bites and you really want to sell it, then consider auctioning it off on ebay. You won't get as much for it on ebay as people on there are looking for a smoking low price.

If you have mods that can be taken off, consider parting those out as you really can't get your money back on those items when you sale the car.

One last thing to consider...if you are unsure of this decision then get a popular car. That way it would be easy to sell it and get something else. I like to think ahead because you never know!;)

It may not make you feel any better or make you change your mind but I have a 4.8 in the UK and travel about 35000 miles per year and currently our gas price is about £0.90 per litre. That's just under £5 or $10 per gallon!

I am happy to pay this hugely inflated price to hear the V8 on full chat. $400 per week I put in the tank on average and enjoy every ounce.

The RS4 was just a blast to drive, but yeah, if I'm worried about MPG I probably shouldn't be looking at that. I like driving a stick though, makes the drive a bit more fun.
For right now I think I'm going to stick with my X5, at least until I know for sure whether or not I'm going to be staying in the US. Thank you all for the opinions and advice.