I'm new on the forum and I have some questions and comments. I emailed mobil 1 and they're supposed to re-release their 0w20 synthetic oil in the second quarter of 06. Where I live at least, we've been out for months. I've also been considering some lighter and possibly thinner wheel/tire combos. I've been looking for some weld racing drag skinnies, haven't had much success because I want to keep my same overall diameter. Are there any aftermarket companies out there making less restrictive header exhaust systems, cold air kits, underdrive pullies, anything of the sort to improve mileage? Also, would lowering the vehicle reduce the aerodynamic drag of the vehicle enough to see a mpg difference?

Yes, its very noticeable when your cornering and your losing very little speed while coasting.

As for that synethitc Mobil 1 0-20 oil yeah its tough to find and expensive too. But just keep checking the major retail stores and I'm sure you'll find it evenually.

As for the rest, I have no experience.

i got around 20 km a liter when i drove a civic 5 spd using advanced hypermiler techniques
and now I drive a salvage nwh20 prius that gets almost to 25 km/l with 192,000 km to date.

Just bought a quart of Mobil 1 0w-20 at Wally World this weekend for $6.22, same price as the other grades of Mobil 1.

By far the most effictive modification one can do to gain MPG is by changing driving habits.
Probably #2 is regular maintenance including tire pressure.

For example our Grand Caravan went from 16-17MPG to lower 20's with just a few minor changes. The biggest change was with my HCH which went from 40's to 60's MPG with vastly modified driving habits.

Same manifold, springs, etc.
Good habits are transferable to any vehicle you drive...present and future.
No wrench required.

Efficient drivers do it better.
1003 miles a tank personal record. 74MPG calculated. HCH1 CVT

I've learned over 3+ years of driving one is that "small" mods (~ 1-2 MPG) are almost impossible to detect. There are too many variables at play in an average drive (weather, temperature, traffic, your mood , etc.) that I've found it nearly impossible to correlate doing X that translated into +Y MPG. So I can't tell you that 0w20 equals +1.5 MPG, but I use it and believe it to be superior to the 5w20 I was using. I can't tell you that psi equals +1 mpg, but I run at 45 psi anyway. I'd say that most folks subscribe to oil + tire pressure + driving style as the main things to address (that don't involve a lot of expense and heroics).

Now I did make an attempt at a lighter wheel/tire setup - managed to drop the wheel weight ~2.8 lbs per wheel by using lightweight wheels (Kosei K-1 TS 15") with Continental tires (195/60/15). So far, I can't say that it's made a difference, other than it hasn't hurt FE. However, it's been a colder winter than the last couple years, so it's difficult to say. I will, however, say that the smooth disk wheels you get stock are going to do more for your wind resistance. I switched up to spoked wheels - while I like the look, they seem to drag more (highway mileage does not seem as good as before).

I'm of the belief now that once you do the standard stuff (oil, tire pressure, driving style), the next big factor is wind resistance. I've read about experiments folks have done by sealing the rear wheel compartment (like the Insight, but they did it with cardboard just for the experiment) and got something like a 2-3 MPG boost. I'd be interested to know if lowering the car truly helps, or if the HCH is already dialed in at the optimum height.

Oh, and this thread may have everything you ever wanted to know about air filter and exhaust mods: http://www.greenhybrid.com/discuss/s...3361#post53361

*** Retired after 65,000 outstanding miles ***