Looking for ways to maximize gas milage for my '00 S40!!!!!

Hi! I have 53k on my S40 and I am obsessed with gas milage!!! Besides "driving economically" which I consider myself very knowledgable, I am looking for any mechanical/aerodynamic and other. ways to increase my MPG. I get an honest 39.5-39.8 mpg on all my "Milage runs" between Boston and Vermont and return. This milage is obtained with a max speed of 60 mph, no A/C, windows up, tire pressure maxed out at the Volvo economy pressure w/low rolling resistance Yokohama Avid Touring S rated, hight test,no extra weight(spare in car),all synthetic oil 0W-30 Mobil 1 and Mobil 1 syn ATF. The only new (untested!!!)addition is a 10" K&N cylindar filter which sits partially in the bottom of my open air box which is serving as a temporary heat shield. I will use this set-up for spring/Fall...cool temperatures that allow me to make milage runs with no A/C, otherwise I go back to stock filter/airbox. I believe 40-41mpg is possible with the new K&N set up, but otherwise I think I am maxed out at 40-41mpg! the ony options I see left is weight reduction...spare tire and shelf and aerodynamic mods underneath and on the sides and top of car! I am making another milage run Wed/Thurs, they are aprox 425 miles and include about 5 miles city driving in Boston. I know that some board members might balk at these mpg umbers and might have questions on how I determine milage, gas up the car and refill etc......Please feel free to ask any questions....and any suggestions are greatly appreciated!!!!!!!!!! thanks, Bill (hope using the General forum is ok, seems to have the largest base)

sounds like you've pretty much maxed it out. I got 40mpg in my 850 turbo for roughly 50 miles or so once. It was purely by neccessity, and I felt really stupid going 53 miles an hour on the highway, but it's good to know I can get it up there.

If you REALLY, in just a clinical sense, are interested in MPG, try taking out as much of the interior as you could stomach. I would say leave the spare at home, but you might need it.

...thanks niko....Idon't want to do the seats! I would do the trunk liner if it weighed 30/35+ pounds but I doubt it' plus it looks like once I got it out...it would never go back! I am thinking of covering up open space under the frame and smoothing out the airflow. I can't really lower the car with the vermont roads being so sh---y. I would like to put some sort of plastic air dam on the grille but no one makes one for the S40, plus withe the hood/grill set-up it would seem hard to attach and keep from flapping! Real small side view mirrows would cut dow on air resistance.......Bill

You could try adding a chip. I know that at least for the 850 people see a 1-2 mpg better difference. So you get more performance and better gas milage. Otherwise you have covered all of the bases. Also do you have a spoiler. I know on the 850 the spoiler will reduce the Cd to .31 from .32. I doubt that would do much for gas milage, but the more aerodynamic the car, the better gas milage it should get in theory.

Or, you could always get a TDI (turbo-diesel) A buddy of mine has a Jetta TDI and get 45-50 mpg no matter how hard he drives it. And if driven conservatively he can easily get 50+ (that's over 900 miles on a single tank) and it's almost as fast as my stock 850 T5! 8sec 0-60 (He has chipped it though)

Anthony, thanks...Idon't have a spoiler....at 55-60 mph I agree with you, I don't think it would make any differance! The chip might help, except arn't they all expensive? Is there a chip geared toward economy driving...or is it all more HP, therefore it takes less gas to maintain a given speed? I have read a few posts on other boards and they either had problems with the chips or they didn't last long. I would want to know how reliable they are!!!! I've done the Jetta Smoker before grest milage....but its not a Volvo! My wife and I have had Volvos for years and don't want to change now! Bill

I wouldn't consider the chip at first. For most people it is hard to get better mileage w/ the added power. You could do an exaust, the lower backpressure could very possibly help with you mpg. A hi-flow cat might do that as well, though they are expensive.

You could also try turning the boost down. www.easternaerospace.com has a step by step for turning the boost up, just do it backwards. Take a turn or so out of the wastegate and it will open slower/ and less which will give you reduced boost at crusing. Though, at your speed it doesn't sound like your in the boost at all, but you are when you accel. Keep that in mind though, I couldn't stand to turn my boost down.

You can also try going one size narrower than stock in tire size. Lighter alloy wheels could also help, but I doubt that they get to much lighter than the stock s40 wheels. You can probably run them at 36-40 psi, though 40 seems a bit much.

I would suggest lowering the car, but you said that isn't an option. How about 1/2 an inch or so? You could just have the stock coils cut to do that.

OH KEEP THE CAR WAXED and clean! If your trying to get every bit of mileage, that would help.

Or, just take a sawzall to what ever isn't useful on the car and get rid of it! LOL

That is true, although I do like the Jetta TDI for the gas miliage it doesn't even compare to the luxury and comfort (not to mention performance) of my 850.