Gas at my cheapo New Jersey service station is edging up to $2 a gallon again, thanks to $50-a-barrel oil. And my 9-year-old Sable wagon is in the shop once more, this time for a new brake line.

Events like these make you think about the joys of owning a new vehicle — one with great gas mileage.

Americans aren’t likely to give up their thirsty SUVs and trucks too soon. I’ve got a pickup myself, and I probably always will.

But for that second car … well, maybe some dinky gas saver would be worth a look.

Just how much could you save?

Car comparison

The current gas-economy champion is the Honda Insight. According to a Web site run by the Environmental Protection Agency, www.fueleconomy.gov, this gas-electric hybrid gets 60 miles to the gallon in the city and 66 miles on the highway.

Assume I’d drive it 12,000 miles a year, mostly around town. At 60 miles a gallon, that’s 200 gallons a year.

At $2 a gallon, I’d pay a mere $400 a year for fuel.

Compare that to an SUV such as the Land Rover Discovery, rated the least efficient SUV by the EPA. It gets 12 miles a gallon in the city, or 1,000 gallons for the same trips to the grocery store and soccer fields I’d make in the Honda. That’s $2,000 a year.

OK, so maybe it’s worth an extra $1,600 a year for the comfort, safety and status of a fancy SUV. Not for me, but perhaps for you.

Still, that adds up.

It’s $8,000 during five years, $32,000 if you keep it for more than 20.

And I’m just getting started.

Investments

What if you were to buy the Honda and invest the fuel savings, which come to $133.33 per month?

Put it into a good stock fund and make an average of 7 percent a year and you’d have $69,500 after 20 years, enough to let you retire a year or two early.

But wait. There’s more.

The Honda goes for about $20,000, the Land Rover for about $40,000.

If you took out a five-year, zero down loan at a typical rate today of 5.8 percent, payments on the Land Rover would be about $770 a month. The Honda would cost just $385 a month.

Let’s assume you always buy the cheaper car and invest a $385-per-month savings for 20 years. At a 7 percent return, that would grow to slightly more than $200,000.

Added to your gas savings, you’re now ahead by nearly $270,000.

On top of that, you’d probably pay a lot less to insure the cheaper vehicle, and repair costs would probably be smaller. Maybe you’d be ahead by $300,000, perhaps more.

The pay off

Of course, in real life you’re not going to get exactly this number. You’d have to figure the turn-in value of each vehicle and the replacement cost, look at inflation and taxes on your investment gains.

But there’s no disputing the fact that choosing smaller, cheaper, fuel-efficient models would save you a fortune over time. Just imagine if you have 30 years left in your car-owning life, or 40.

Many of us do need a big vehicle every once in a while, but it’s probably cheaper to rent one occasionally than to own one all the time. Not many families really need two big vehicles every day, do they?