Diesel Cars Do Not Always Equal Dollars Saved

Our love for the oil-burners is no secret here at Jalopnik. Especially if said diesel motor is in a wagon that will allow you to row your own gears. However, outside of our circle, diesel is not terribly popular in the US market. In today's Morning Shift, industry experts are predicting that we will see a lot more diesel motors in the coming years. I think this prediction is a little ambitious when you start looking at the numbers. For the purpose of this comparison I am going to leave pickup trucks out and just focus on passenger cars.

Often the math doesn't work-

For most buyers there are two main strikes against diesel motors. 1st the motor itself adds more cost to the car. For example a VW Pasat 1.8T Premium with Sunroof 26,695 a similarly equipped TDI Passat is 28,675. VW claims that the new 1.8T motor in the Passat will get 34mpg hwy, while the TDI should result in 40 hwy (important to note that the city MPGs are 24 and 30 respectively).

The second strike is diesel fuel is more expensive. The average cost of regular fuel nationwide is 3.56/gal while the average national cost of diesel is about 4.02/gal. Using Calculator.net's fuel cost calculator, if the owner of the 1.8T drives 10k miles a year they will spend about $1,047 in fuel costs. If the Passat TDI driver travels about 10k a year they will spend about $1,000 in fuel costs. Of course other factors have to be taken into consideration regarding what type of travel, how much stop-and-go etc… but all else being equal given the efficiency of the new 1.8T it would take quite a while to recoup the extra cost of the TDI motor. I would say that the extra torque is probably worth it, but your average buyer might not see it that way.

Now when you compare the TDI Passat to other mid sized vehicles from competing brands the value proposition drops even more. The Mazda6 gets upwards of 40 mpg with the SkyActiv motor and a similarly equipped Mazda6 (no sunroof) has an MSRP of 25,865.

But if you want a luxury car-

The situation changes when you move up-market into the luxury zone. The BMW 535 sedan starts at 55,100 while the 535d has an MSRP 56,600. I'm comparing the 535 and 535d because they have similar performance characteristics as both cars will hit 60 in under 6 seconds. If you are not concerned about performance than the 528 ($49,500) is your car. BMW rates the 535 at 30 mpg hwy and the 535d gets 38 mpg hwy. But because German luxury cars require premium fuel the cost gap narrows significantly. According to AAA the average price for a gallon of premium is about $4. So if the 535 owner travels 10k miles a year, they will pay 1,333 in fuel costs while the 535d driver will only spend $1,052. While it would take the 535d driver about 5 years to break even spending more on diesel motor, the reality is most mid-size luxury sedans are not purchased they are leased. You can lease either a 535 or 535d for 539/mo. So if you are going to lease a turbo-6 5-series, get the diesel.

Also in case you were curious, Audi charges a $2400 premium for the TDI motor over the 3.0T while BMW only up-charges 1500 for their diesel. So a TDI purchase over a gas motor might not be as wise. I was not able to compare a 3.0T lease to a TDI on Audi's website so if you are interested talk to your local dealer.

When it comes to choosing whether or not a diesel motor is for you, it is important to examine what you want in a vehicle. I still maintain that the TDI Sportwagen is a great daily driver because it offers a nice combination of practicality, efficiency, with a dash of fun-to-drive. Diesel motors are also known for their longevity so if you plan on keeping a car for awhile, this is something to consider. I hope there are more diesel options in the future, but your average buyer spending 35k or less, they should run some numbers before making a decision.

Do you own or have considered buying a diesel? What factors influenced your decision?

I'm Tom and I run AutomatchConsulting.com; I also write articles about car buying. If you have any questions about the car-buying process feel free to drop me a line in the comments or find me on Twitter @AutomatchTom and Facebook.com/AutomatchConsulting