One thing that helped the mileage on the first two was that I was driving lots of miles and they were mostly highway miles. When gas was low, I was driving 7-800 miles per week. When gas started to go up, I had dropped to 500 mpw. Extra high, I had dropped to 240 mpw. Totally out of sight, I had just retired and did only local town driving mostly. So, the price of gas hasn’t affected me much yet.

I did use a lot of good tips to get better mileage – drive 55-60 on cruise on hwy’s, shut car off or put in neutral if stopping for more than 10 seconds, be light on the takeoffs and stops, park so you can pull forward, etc.

I do know how these figures are because on every car I have had since 1987 I have kept meticulous records on the cost of gas/oil, maintenance, and repairs. Right now my Wagon is costing me an average of $80.00 per month for all repairs & maint. As long as it stays below $120, I will not buy another car. We bought this car in 2005 and it has served us well.

Actually, if I need to buy another car, it will be used and I will pay cash for it. I’m one lucky old retired lady with an adequate EF.

What we are really doing is pricing a capital asset. A good way of doing this is to estimate the annual cash flows (Positive and Negative) for things like the purchase price, maintenance, fuel, etc… and then discount each years cash flow to put it in present dollars and then sum up the years.

What is the discount rate? Well you could choose inflation, you could choose a number higher to accounts for your opportunity cost as well.

$100 today is only $42.24 10 years from now at 9%
$100 today is only $67.56 10 years from now at 4%

Were we honest with ourselves, most would admit we drive a lot of purely discretionary miles over the course of a year.

One question: do you find that you get dragged down by some of the negativity and trolls in the comments? I was just thinking how I’d feel in your place … I’d probably be in therapy like every day =). Maybe it’s just me but it seems like there is a lot of non-constructive type criticism.

Also, it always makes me chuckle when there are people that are like “well, I don’t agree with that so I’m never reading your blog again, hmmph.” As if writing one thing they find questionable makes you a pariah for life to them. I mean there are several things you’ve written that I don’t completely agree with but that just seems really weird to me.

I would like someone to discuss somewhere the cost of replacing the batteries on the newer hybrids. I have been told by several people that the cost will be in the thousands! This isn’t a cost that can be put off indefinitely through careful maintenance, as can be the case with a combustion engine.

On a related note, I disagree with the whole premise of “you will save $xxx if you make this decision. In real life, you are actually lowering the amount you will be spending.

The term “savings” tells me that you are actually putting money into a savings account of some kind. Unless you are truly doing that, I don’t think the word “save” is appropriate.

We should start spreading the phrase “reduce the amount you obligate yourself to spend” instead. It just rolls off the tongue and is more accurate a description in most cases.

Also, I wanted to say that I was happy to see the last paragraph of the post. Too often it seems that the entire message gets lost when readers disagree with one of the details, assumptions, or examples that are given. I’m glad that Trent is trying to keep everyone’s focus on the primary point of the article.

You might want to think carefully about that particular logic. Car crash safety is not just about who has the biggest car, it’s about whether the cabin deforms and traps you in a fire, or whether the engine moves from the impact and pushes the pedals up and breaks both your legs. In Euro NCAP safety ratings, a 2004 model Ford Focus outranks a Landrover Discovery. If you have a big safe truck then fine, but don’t assume a truck is safer just because it’s big.

Meaning, you can get the most fuel-efficient car in the world, but if you don’t maintain your tire pressure, change your air filter, tune your car up regularly etc., then you are just “spinning your wheels”.

Pardon the pun

I would also like to add that I liked the last section. It was like something a much more polite version of Ramit would have said. If you think an assumption is wrong, change it! The math isn’t too difficult to work through yourself.

In cases like that, you’re better off *under*estimating the future cost of gas – or even just going with today’s numbers, to decide if it’s worth the price difference based on your own driving.

Otherwise, between two cars at about the same price, the more fuel efficient car will always be the cheaper to drive fuel-wise, regardless of what the price of gas does.

Another point to consider is how much the car costs. If it’s a little less fuel efficient, but less money, it might come out to a wash. If, over the life of the car, a Corolla will save you $2000 in fuel costs, but the Focus costs $2000 less then it’s about even. Just a thought, since more fuel efficient cars are often more expensive than other comparable cars. We just went through this process, and that’s what I noticed about it.

BTW- I don’t think this is a rehash. I couldn’t remember you talking about this recently, and while this is kind of a “no-brainer” for me, I thought the info was useful. I was very proud of you for not using the word “Prius”! And while I don’t agree with everything you say (and sometimes the tone is annoying), I still enjoy the blog. Just thought that will all the negativity floating around lately, you could use the encouragement! I’ve been reading for nearly 3 years and I’m not going anywhere!

On to the article. I know that my husband gets markedly lower mpg than I do. The difference is in how we drive. DH=Mario Andretii on steriods. Me=80 grama on a Sunday drive. Here’s the point, there’s like a 10mpg difference on any vehicle that we drive. So figure in how you drive. That, IMO is the most important factor in determing gas milage.