So while doing some research on another forum dealing with mpgs I ran across these acronyms. P&G and HAI. Now after reading up on them I have a growing curiosity of wether or not they work. If your not familiar with these I'll give a brief description of what they mean.

P&G: Pulse & Glide - In a nut shell this means if your goal cruising speed is 55 mph, then you accelerate a little higher (65 mph or so) then shift into neutral and coast down to 45 -50 and repeat. According to many people on this forum this is much more fuel efficient compared to keeping a constant speed where your RPMs remain above idle. It makes sense on paper. You maintain the same average speed but RPMs stay at idle much longer.

HAI: is simple it stands for hot air intake. They claim heating up the air temp entering the intake will increase gas mileage. I know the warmer the air, the less power you make so maybe thats the connection there but idk.

They also go on to say that replacing the stock thermostat with one that allows the engine to run a little hotter will also increase miles per gallon.

Does anyone have any insight on wether these methods are the case and actualy work on a Saturn. Specifically an SL2.

I am going to try the P&G method on my next tank to see if I get some additional miles out of a full tank.

 

I don't know if the "pulse & glide" will work or not, but unless you are in the slow lane (and maybe even there too), the constant 20 mph swing in your vehicle speed is gonna irritate the drivers behind you. Prepare yourself for an increase of single digit finger waves...

 

Sounds good on paper, sounds damn stupid on the road. I agree with Ocean so prepare yourself, and keep an eye open for handguns hanging out of passing cars.

 

Yeah I'm not too worried about the hand gestures lol. If they give me one I'll give them two right back! I can't hold on to my steering wheel anyways because of my stinky new steering wheel cover.

But on a serious note, this isnt something that you would do all the time. Just on occasion when you werent in traffic and use it with declines and things of that nature. You would obviously have to be smart about when you choose to do it!

 

Also this is considered to be an "extreme measure" to get extra mpgs out of a car. This comes from guys who get 40-50 mpg out of cars that tipically get 30 at best!

 

its funny because no matter how hard or how grandpa I drive my saturn I can never get above 24 MPG (or below 22.5 honestly, always somewhere in that range). I used to get 28-29 before I did the motor. maybe its the winter blend (I use the ultragauge for the mpg)

idk about other cars, but changing the tstat in a s-series to make it run hotter could be an engine killer imo.

 

Wow thats the lowest I've heard of. How much did you pick that ultragauge up for? I was looking into scanguage but they are like $150 +.

 

Its only like $50, its useful. Shows everything the computer reads, plus fuel economy, acts as an extra trip meter and timer, and reminds you every X amount of miles to change your oil. Plus, it will read and erase engine codes!
http://www.ultra-gauge.com/ultragauge/index.htm

Now that I remember, my egr valve is giving me problems and I need to change both my O2 sensors, so that is probably contributing to it haha.

 

I'm not sure if I agree with that theory cause I travel a lot and the best way to conserve fuel is to run your cruise control. If you put it in neutral and then have to bring rpms up when u put it back in gear I would think that would take more fuel because you are fluctuating the throttle .

 

I can personally testify to the effectiveness of these methods... My last daily driver was a 2007 Chevy Malibu (2.2 ecotec, 4T45E trans), and the trick to P&G is to kill the engine while you're coasting in neutral(OF COURSE make sure the transmission will handle this, AND make sure you understand what happens when you lose engine power while the car is in motion)... I never did this in traffic, but on rural roads, it works okay...