Green guilt-ridden

My sisters and I are Vegas-bound next week. I’m the official travel arranger and as a budget-conscious traveler, I’ve been snagging good deals starting with the airfares and lodgings. But now that I’m doing the car rental, I’m in a fix.

We’re definitely getting a midsized car. We’ll be doing a lot of long driving on highways. I know that we should rent a hybrid, but it’s expensive. Here’s why:

Assumption: an estimated 600-mile trip total with estimated gas price of $4.20 per gallon (either in NV or UT)

For a hybrid:
estimated 60 miles per gallon
a 600-mile trip would require 10 gallons
rental fee – $325 (courtesy of Orbitz)
gas expense total – $42
TOTAL: $367

For a non-hybrid:
estimated 20 miles per gallon
a 600-mile trip would require 30 gallons
rental fee – $125
gas expense total – $126
TOTAL: $251

Costs-wise, it seems a non-hybrid is the way to go, unless I computed it the wrong way. But a part of me thinks that the savings from airfares and lodgings can very well be directed to the hybrid rental.

So now I’m confused. Help!