Originally Posted by MobyDick22

First off, I didn't fudge numbers. There's a bigger difference between the city and highway mpg on the diesesl so it was a fair comparison. But yes I could have taken an average. I feel like most people drive in the city which is why I chose lower numbers. I also did not know the ecoboost is a 10,000 mile oil change so thanks for pointing that out. Second, did you not read the whole thread? I specifically mentioned the fact that "a diesel costs more initially"...twice actually. My point was that people think since the fuel is more expensive, it's a waste of money when it really comes out close to the same.

Originally Posted by MobyDick22

I have been following the Ford light-duty diesel craze over the past few years and while I do understand the initial cost of the diesel engine is greater than the gas engine, the diesel is a far better choice for the long term. As a civil engineer, I tend to crunch numbers out of habit, so being curious, I did some simple math to compare costs. Bear with me...

According to ford's website, the 2011 f150 4x4 gets 16city/21hwy mpg. While I don't have a reference for the articles, I have seen multiple times where they claim the light duty diesel will give a 20% increase in fuel economy. This puts the diesel getting 19.2city/25.2hwy mpg. I live in north Texas where current fuel prices are $2.90 for gas and $3.20 for diesel. Considering those prices, let's compare over a 60,000 mile period with slightly above the city mileage.

Gas f150 - Using 17 mpg...
3530 gallons used = $10,237
Oil change every 3000 miles, roughly $40 per visit = $800
Total cost over 60,000 miles = $11, 037

Diesel f150 - Using 21 mpg...
2858 gallons used = $9,145
Oil change every 10,000 miles, roughly $100 per visit = $600
Emissions additives, roughly $100 per oil change = $600
Total cost over 60,000 miles = $10,345