golfrewind.com

Since gas is so expensive and seems to be a topic of interest lately...

I just bought a new leftover '07 Chevy Cobalt. It's good on gas and it has a digital readout of gas mileage that the driver can reset at any time. It seems to be more accurate and stable than the digital readouts I've seen in cars from the late 90's and early 00's.

I figured I'd play with it and test some different gasolines for mileage since I have some sort of compulsiveness with numbers and statistics. Anyway, I've made the following conclusions.

33.2 MPG with Shell gas
33.8 MPG with Exxon gas
34.2 MPG with gas from a Turkey Hill Mini Mart (these are probably just a regional chain)

All ratings are made during the same driving conditions of approx 75% highway travel, 20%country roads and 5% stop-and-go driving. All MPG ratings are based on the average of 2 tanks of 87 octane gasoline. Speed of driving was typically 5 to 10 MPH over the speed limit.

I was always under the impression that the fuel economy of different gasolines would be of a wider margin. I guess only time will tell as I will test more types of gas in the future.

Also, since the readout stabilizes quickly, I experimented with driving uphill and downhill. On a stretch of a country road (approx. 4 miles) with a steep incline, my vehicle only achieved 19.0 MPG. On the other side of the mountain, the road had a decline of a similar grade and during that stretch of road I achieved 38.0 MPG. Interestingly enough, the average of the uphill/downhill driving yielded poor overall fuel efficiency. So, the moral of the story is choose the flatter route to your destination for better fuel economy!!!

Unless you have one of the hybrids with the regenerative power systems; their mileage is better in stop-and-go and hilly terrain then the flat route. My experience is with the Ford Escape Hybrid but results should be similar for other mfgs.

That's a good point. I notice all the hybrids are rated better for city than highway. I am of the understanding that driving them at lower speeds uses more of the electric power and less of the gas. Is that true?

A guy who works for me suggested getting something called a "Tornado," a device that causes a vortex effect in the intake system. He told me I'd get 3 more MPG for sure. I'm willing to give it a try.

Yes, in city driving the gas engine is called on when needed to assist the electric motor and the opposite is true on the highway. Energy from braking is used to recharge the electric motor's batteries.

The Tornado works...like he said, boosts mpg at least 3 and HP at least 2 or 3. Only problem is that more HP usually = less mpg because you want to stick your foot in it. If you can resist the urge to punch it then the Tornado will save you money.

Shade

You are lucky that petrol is so cheap in america,just now we pay around 92p per litre thats $1.84 A LITRE

I haven't put the Tornado in yet, but I've tested Sheetz 89 octane gas and it gave me 36.3 MPH average for 2 tanks. I was always under the impression that their gas was crummy, so I was skeptical buying it... worked out pretty good!

Use Super Unleaded for my Porsche, over here in the UK thats usually 98p/ltr ($1.97) ~~ £1.05/ltr ($2.12)

Average 13-18 MPG

You're more fortunate than I, sir. Fast cars are nice, but I'd rather spend my money on other stuff. This year, I'll gross about $70k and I still adore my $15,000 Chevy for the fuel economy.