BMW 3 Series Beats C-Class by $541 Over Five Years

Our calculator puts the 2020 BMW 3 Series at $39,402 to own for five years. The 2020 Mercedes-Benz C-Class comes in at $39,943. That is $541 more for the Mercedes, or about $9 more per month ($657 vs $666).

The BMW is the cheaper car to own. Not by a lot, but it wins on purchase price, depreciation, fuel and insurance. It loses on exactly one line: maintenance. If you are choosing on money alone, the answer is the 3 Series.

The gap is mostly fuel, and the Mercedes starts behind

A $541 gap sounds like it should have a single villain. It has a few small ones.

Fuel is the largest. Over five years the C-Class costs $14,260 to fuel, against $13,688 for the 3 Series. That is $572 more for the Mercedes. Monthly, it works out to $238 vs $228, a $10 difference.

Depreciation is next. We assume you pay $17,400 for the C-Class and $16,400 for the 3 Series. Over five years the Mercedes loses $4,965 in value and the BMW loses $4,678. The Mercedes costs you $287 more there. You pay more up front, and then it sheds more.

Insurance adds $149 more for the Mercedes ($8,932 vs $8,783). That is our estimate based on each car's value and class, not a quote. Your own number will differ based on your age, ZIP code and driving record, so get real quotes before you commit.

Add those three together and the Mercedes is $1,008 behind. That is more than the $541 final gap. So what pulled it back?

Where the Mercedes claws back money: maintenance

Maintenance is the one category where the C-Class is cheaper. Our calculator has $6,671 for the Mercedes and $7,138 for the BMW over five years. The BMW costs $467 more.

That is a real gap, and it cuts against the idea that German luxury cars are all the same. The 3 Series has the heavier service bills here, and they are lumpy. Year one is $2,025 for the BMW vs $1,892 for the Mercedes. Year five is $2,978 vs $2,783.

Still, $467 does not erase $1,008 of extra cost elsewhere. The BMW's maintenance penalty is the only thing keeping this from being a lopsided result. As it stands, it is a narrow win.

Repairs are identical in our model: $4,860 over five years for each car. No edge for either side.

Year by year: the C-Class is pricier early, then the lead flips

The yearly totals tell a more interesting story than the five-year sum.

BMW 3 Series, years one through five: $8,366, $6,786, $7,154, $7,330, $9,766.

Mercedes C-Class, same years: $8,454, $6,963, $7,301, $7,468, $9,757.

The Mercedes costs more in each of the first four years. The gaps are small: $88 in year one, $177 in year two, $147 in year three, $138 in year four.

Then year five flips. The BMW costs $9,766 and the Mercedes costs $9,757. The C-Class is $9 cheaper in that final year, and it is the only year it wins.

The reason is that big year-five maintenance bill. The BMW's $2,978 is $195 higher than the Mercedes' $2,783. That swing is enough to wipe out the Mercedes' fuel, insurance and depreciation penalties for one year.

The pattern matters if you keep cars a long time. The BMW's lead is built in years one through four. If you plan to sell before year five, the gap in the BMW's favor is slightly wider than the headline. If you keep the car beyond five years, expect the two to run about even, with the Mercedes possibly edging ahead as the BMW's maintenance stays heavy.

Both cars have an ugly first and last year. Year one carries the heavy service catch-up and registration ($91 each). Year five is the most expensive of all, at nearly $10,000 for either car. Plan for that, not the middle years.

Fuel: the Mercedes drinks a little more, and it adds up

Fuel is the biggest single category in the gap, and it is also the one you control most.

Our calculator puts the 3 Series at $228 per month in fuel, averaged over five years. The C-Class is $238. That is $10 more each month for the Mercedes. It does not sound like much, and it is not. But over 60 months it becomes the $572 gap above.

Fuel costs also rise each year in our model, since we assume prices creep up. The BMW goes from $2,630 in year one to $2,847 in year five. The Mercedes goes from $2,740 to $2,966. The Mercedes is more expensive every single year.

If you want the MPG ratings for either car, check the 2020 BMW 3 Series on fueleconomy.gov and the 2020 Mercedes-Benz C-Class on fueleconomy.gov. Trim and engine matter a lot, so look up the exact version you are shopping for. Your own commute will move the real number up or down.

Reliability: the repair bills match, but the risk is not zero

Our model gives both cars the same repair cost: $4,860 over five years, climbing from $540 in year one to $1,530 in year five. That is nearly triple in four years.

That is an average. Averages hide the bad surprise. A single failed electronics module or cooling system part on a luxury German car can cost more than a whole year of the average. You can check each model's reliability record and typical repair costs at RepairPal before you buy. Look at how often owners report unscheduled shop visits, not only the average annual cost.

I would not pay extra for either car on the basis of reliability. Neither earns that. Both are complicated machines with a lot of sensors, and by year four the repair line is already $1,170. Buy a pre-purchase inspection from an independent shop, and consider setting aside the repair money in a separate account.

The point is that reliability does not decide this comparison. The repair lines are the same. If you hear a friend say one of these is the safer bet, ask for the evidence, then check it against RepairPal.

The verdict: who should buy which

Buy the 2020 BMW 3 Series if you want the lowest cost and plan to sell within four years. It is cheaper to buy by $1,000, cheaper to fuel, cheaper to insure and slower to lose value. You will pay more at the service counter, so budget for that big year-one catch-up of $2,025 and the heavy year-five bill of $2,978. If you sell before that last stretch, you skip some of the worst of it. This is the right car for a driver who commutes a lot and watches the monthly budget.

Buy the 2020 Mercedes-Benz C-Class if you keep cars for the long haul and care most about predictable service costs. Its maintenance is $467 cheaper over five years, and in year five it is the cheaper car to run. If you like the C-Class interior or the way it drives, the penalty is modest: $541 over five years, or $9 a month. That is the price of a couple of lunches per month. Pay it if you prefer the car.

But be honest about what you are doing. If you pick the Mercedes, you are not buying a cheaper car. You are paying about $541 for a preference. If you cannot name the preference, buy the BMW.

One last caution. Both cars cost nearly $40,000 to own over five years, with a $16,400 or $17,400 purchase price as a small part of that. The sticker is the cheap part. Fuel, insurance and service make up most of the bill, so shop on total cost, not on the asking price.