Most people are driving a larger vehicle today than they were a decade or two ago. While that can be a response to lifestyle changes, another key factor in buying larger vehicles is "brand migration."

The Honda Civic was introduced as a subcompact in 1972.

In 2014, you can still buy a Civic, but it’s no longer a subcompact.

Today’s Civic weighs more than twice as much as the original, is over a metre longer, and is now classed as a compact.

The Honda Accord debuted in 1976 and as a compact, it was seen as a step up from the subcompact Civic.

However, today’s Civic is significantly larger than the original compact Accord. And today’s Accord has grown so much  in 2008, it was classified as a full-size car.

But Honda couldn’t compete without a small, inexpensive vehicle, so in 2006 it introduced a new subcompact.

Even though the Fit is classified as a subcompact, it weighs almost twice as much as the original subcompact Civic and is about the same size as the original compact Accord.

This is known as brand migration — a way for marketers to get us to buy larger, more luxurious, more expensive cars over time.

Marketers gradually migrate a model name upward onto ever more expensive cars, while at the same time applying a new, unfamiliar name to the original, less expensive car.

This helps consumers believe we’re not being unnecessarily extravagant, even though we’re spending a lot more than we used to. We can keep buying Civics and convince ourselves we’re still being practical and frugal, when in fact we’re buying a much larger, more luxurious car.

The same upward migration has occurred with another popular car, which debuted in 1966.

Similar to Honda, today’s compact Toyota Corolla weighs almost twice as much and is almost a metre longer than the original subcompact Corolla.

The truth is, if you were originally a Honda Accord buyer, over the years you could have sensibly moved to a Civic and eventually a Fit without losing size or comfort.

Most drivers never do that, though, because the ads have convinced them that doing so would be moving down, which nobody wants to do.

The key to avoid being taken in by upward brand migration is to ignore brand names altogether. Instead, concentrate on what you actually need and the price you can actually afford, whether that means buying a Honda, a Toyota or a transit pass.