Tag: cars

How to replace the engine air filter in a 2006 Subaru Impreza

I neglected to follow the maintenance schedule for replacing my engine air filter and realized that it had been over two years since I last replaced the this part. The replacement process is simple and also relatively low-risk, meaning that it is unlikely for you to screw up, hurt yourself, or destroy your vehicle.

In the 2005-2007 Subaru Impreza series (non-WRX), the replacement process is quick and simple. The engine air filter is situated on the passenger side of the engine.

Access to the engine air filter is on the passenger side under a plastic vent cover.
Access to the engine air filter is on the passenger side under a plastic vent cover.

The housing includes two clamps that can be released without any tools:

Push the clip away from the edge of the cover to release.
Push the clip away from the edge of the cover to release.

The plastic vent hood can then be lifted up vertically to expose the engine air filter. The tubing should have a little bit of give and offer you plenty of room to move the cover aside. My old filter was disgusting and pitch black:

This is what a dirty engine air filter looks like. Don't let that happen to you.
This is what a dirty engine air filter looks like. Don’t let that happen to you.

Typically the airflow through the filter is not through the center of the filter but rather from the side. Most of the time only half of the filter becomes dirty simply due to the positioning of the airflow. My filter was black throughout, as I clearly had rotated it around to extend the life of the filter.

This is what a clean engine air filter looks like
This is what a clean engine air filter looks like

I ordered my air filter through eBay for $8.05. You can simply take out the filter and replace it with a new one. The dealer charges $40 plus another 0.25 hrs of labor @ $100/hr. The entire job took me about five minutes, which included the time it took the pictures for this entry. That is an insane amount of cost savings especially since I didn’t even have to take the car to the shop! I could have even splurged and used a high-end oil-based filter that will outlast the life of your car (rated to be used for 1 million miles!)

Have you replaced the engine air filter on your vehicle before? Is the cost and time savings worth your pay scale?

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Should I buy the BMW X5 xDrive 40e Hybrid luxury SUV?

Should I buy the BMW X5 xDrive 40e Hybrid luxury SUV?

I previously assessed the economical merits of driving a hybrid car. The vehicles I reviewed were more wallet friendly and not frequently seen in communities whose annual income exceed $200,000. Mazdas and Priuses aren’t typically considered luxury cars. If you cruise down Highway 101 in the greater Los Angeles area, the luxury cars you see are Teslas, Mercedes AMGs, Hummers, Maseratis, and high-end SUVs. If you stroll down any of the tree-lined neighborhoods of Boston, you’ll see Range Rovers galore. Among this wide range of luxury vehicles, only a handful reflect consideration to the environment.  This leads up to our next question: if you can afford to splurge on a luxury car, should you aim to be environmentally responsible as well? After all, wealth and environmentally conscious is always morally superior, right? ?  This is where hybrid vehicles and electric cars come in. Is it worth it to buy a luxury environmentally conscious vehicle?

I recently received a flyer in the mail advertising the new BMW X5 xDrive 40e Hybrid SUV from our local BMW dealer. They were willing to deliver the SUV to your doorstep to test drive! Business must be tough these days, especially with sub $2/gallon gasoline in most of the country (not in California!) This level of service for luxury vehicles is actually not rare at all—Ferrari dealers will deliver your vehicle and pick it up for service from your doorstep.  However, I never considered BMW’s to be in that league. Nothing screams more of moral superiority than a 5000 lb luxury hybrid SUV delivered to your doorstep.

I looked into the specifications of this monstrosity: luxury German parent company, assembled in South Carolina, $63,000 base price tag, with fancy Bang & Olufsen speakers. Acceleration from 0-60 is less than 7 seconds, and the electric motor can clock in somewhere between 13 to 18 miles. Prominent logo in the rear hatch that proudly reminds others on the road that this monstrosity has an electric engine as well.

Does this car save you gas?

A driving range of 13-18 miles on electric power sounds absolutely horrible. While I hate commuting, I still ended up living about 13 miles away from my workplace. If I owned that car, I’d still have to eat some gas on every roundtrip commute. If I travel between offices and the hospital, I’d run out of electric power halfway through the day. You have to recharge your charge every single night to make sure the battery stays charged.

BMW says that the average errand involves running to the grocery and department stores and is less than 10 miles so the X5 Hybrid is covered. While this may be true, why should anyone ever need to haul 5000 lbs of vehicle to buy groceries? No one should ever lug around that much weight to buy groceries even if you’re buying 100lbs of dog food!

You’d be better off driving a smaller, more fuel efficient car if your sole aim was to save gas.

Who should own this car?

All practicality aside, the BMW X5 is actually a very nicely designed SUV. The engine under the hood and the interior design exudes luxury. This car makes one of two statements about its driver:

  1. I am filthy rich and enjoy luxury cars or
  2. I am in over my head and paying for this car’s lease through my biweekly pay check.

I’d say that if you’re going to drop $60+k on a luxury SUV, there are far worse vehicles (read less reliable and less practical) to spend your money on. The hybrid aspect of the car isn’t going to save you much money, but sounds a whole lot more practical than driving a hybrid Porsche.

Since I am a firm believer of stealth wealth, I would probably not own this car under any circumstance. With a fancy car, I’d want to make sure to keep it in the garage to protect it from the elements. I’d be wary of it being in the supermarket parking lot, lest some careless customer slams their car door onto mine. I’d worry about people breaking into the car, since a luxury car attracts attention.

If this car does strike your fancy, make sure that it represents a relatively minor portion of your wealth.  Any luxury splurge like this shouldn’t exceed 1% of your total net worth. For a $60,000 car, this means that you should have at least $6 million of net worth.  I understand that this is an incredibly conservative assessment, but this is a pricey splurge.

Would you buy a BMW X5 Hybrid?

The Practical and Basic Ways to Inspect Your Tires

I’ve written before about low risk practical measures to maintain your vehicle such as changing the headlights and taillights. Today we will discuss two fundamental principles of wheel care: tire pressure and alignment.


Tire Pressure

As part of my routine car maintenance, I typically check my car’s tire pressure to make sure that they are properly inflated. Insufficient air in the tires will result in decreased fuel economy and uneven wear. Overinflated tires will also result in uneven wear on the central treads. Tire pressure maintenance is particularly important in cold weather, as air pressure decreases as the molecules slow down with decreased temperature.

The first step in management of tire pressure is to know what is a normal number for your car. Most cars will have a detailed chart on a sticker in the frame of the driver’s side the car:

recommended tire pressure in front door

Many vehicles will have different ratings for the front and the back tires depending on the expected load. The photo above shows that my 2006 Subaru Impreza has a recommended tire pressure of 33psi in the front tires and 20psi in the back. Note that the tire pressure in the spare tire is much higher (nearly double) that of the standard tire. Since the spare tires are typically smaller than the standard tires (less contact area), a higher pressure is required to hold up the weight of the car.

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Newer vehicles actually have pressure sensors built into the valve stems of the car and will notify the driver whenever the tire pressure is out of range. If your car doesn’t have sensors, then all you’d need is a tire pressure gauge from any department or hardware store. To check your tire’s pressure, simply unscrew the valve cap and place the gauge to the Shrader valve.

To refill your tires, either add air via a pump at the gas station or use a portable tire inflator/starter.

Wheel Alignment

Wheel alignment is a more subtle phenomenon that is critical in maintaining durability of your tires. Misaligned tires will wear unevenly. The key to measuring wheel alignment is to check the tread depth of your tires. The magic number is that you need to keep the tread depth to be thicker than 2/32”. To measure the tread depth, use a ruler gauge:

Check tire tread depth with card ruler

Or you can also use a penny to track the tread depth. Please the penny upside down in the groove of the tread and if you see Lincoln’s head, then your tread depth is <= 2/32”. Uneven tread wear will result in decreased traction on the pavement and decreased control during slippery road conditions.

check tread depth using lincolns head on a penny

Check every tread in your tire (outside to in), and see if the depth wear is even. I recently noted that my outer treads were worn asymmetrically with the inner treads. This results from positive camber, and means that I should look into my suspension or take my car to get the tires realigned. I take my tires to Walmart every 7500 miles to rotate (I get free balance and rotation since I purchased the tires from them), but clearly the mechanics never did note uneven tread wear on all of my tires. YMMV on discount service centers!

How often do you inspect your vehicle's tires?

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When Is A Hybrid Car More Cost Effective Than A Traditional Car?

When I was choosing to buy my first car after finishing my training (read: eminent income boost), I agonized over a handful of dissonant choices: fancy vs budget, SUV vs sedan, SUV vs hatchback, sedan vs hatchback, hybrid vs traditional, and American vs Japanese vs European. Or should I just let loose and buy a Hummer?

I strongly considered getting a hybrid vehicle, not because I am environmentally conscious, but I did not want to spend as much of my time waiting at the pump getting gas. At first glance that’s a silly requirement, but you can lose 20 minutes every one to two weeks at the pump. Combine that with your daily commute and you have wasted at least 5 hours of your week in your car. The environmental advantages of a hybrid have been debated online as well, as some claim that the energy consumed from production of hybrid car batteries and components vastly outweighs any savings from pollution reduction.  While the government has ceased giving tax breaks to hybrid vehicle owners, the price differential between hybrids and their gasoline counterparts has become marginal over the past few years.

I decided to look at two categories of cars:

Mazda 3 vs Toyota Prius

I test drove both of these cars and decided that there were very similar in price point. A mid-range Mazda 3 came in roughly at $20,000 new while a Toyota Prius was around $24,000 new for the base model. I did note that the Toyota dealers in the area often added many accessories into the car, which often drove up the sticker price at least $1,500. I also considered used vehicles for added savings but unfortunately did not have the cash to make a full payment on the car, and there were limited used car options in my area at the time I needed a car. Alas that is the life of a poor doctor!

The Mazda 3 and Prius were advertised to support a 39mpg and 48mpg highway fuel economy, respectively. This was impressive since the Mazda is not a hybrid vehicle! I decided to compare the annual cost of gas for each car and made a graph:

Comparison of Gas Expenditures Between Mazda 3 and Toyota Prius

At the time I was deciding to buy a car, car prices were at an all time low, around $1.85/gal! During the past two years, I believe that the higher I would have paid for gas was around $2.60 a gallon, with averages in the $2.20 range. For the purposes of the graph, I assumed that gas was $2.50/gal. At 15,000 miles per year, the difference in gas expenditure between the Prius and the Mazda would have been $180.29! Assuming that the Mazda 3 and Toyota Prius are equivalent cars (they are not), is it worth spending $4,000 more up front for the Prius to save around $180 a year in gas? Obviously the breakeven point could change if I clocked in more mileage per year or the price of gas were higher, but cost-wise, it did not make sense in my situation to drive a Prius.

Lexus ES300h vs Lexus ES350

What if I wanted a luxury car? A hotshot doctor shouldn’t be driving a common car, right? We need leather seats, power, and class! I looked into a Lexus ES350 and its hybrid counterpart, the ES300h.  The advertised prices were $38,000 vs $40,920, respectively. There doesn’t appear to be as much of a price differential. The fuel economies were 31mpg on the highway for the ES350 and 40mpg combined for the hybrid. At 15,000 annual miles, the hybrid would save $326.61 if premium gas were $3/gal (yes I live in an area where gas is cheap!)

Annual Cost of Gas Comparison Between the Lexus ES350 and Lexus ES300h


At any rate, it is clear that the gas cost benefit of a hybrid vehicle increases as the price between the hybrid and its gas equivalent diminishes. The breakeven time will of course diminish as price of gas rises and number of miles driven increases (you don’t need a graph to understand that). The estimates that I used compared highway driving for the gas vehicles to combined driving for the hybrid (highway fuel economy for hybrid cars can actually be less than city driving since the gas engine has run).

There is also a huge discrepancy between the cost of the hybrids from model to model. My example of the Lexus ES350/ES300h is seems to be an anomaly at a $2,000 difference. The Lexus LS460 commands a price of $72,000 while its hybrid counterpart (LS600h, albeit with more features) comes in at $120,000!

Frankly, if I had the money to buy a used vehicle with cash, I would have done so. I opted for the best choice I could afford at the time, a Mazda 3 from the dealer. I was able to finance (cringe) the vehicle at 0% APR for 5 years! That’s right, no interest for the life of the loan. I currently average around 38-41mpg combined driving (no hypermiling tactics used) on the car and drive around 16,000 miles a year (MMM would give me a face punch for driving so much, but that story is for another time).

My selection against a hybrid (Prius or Civic) works for me because gas is so inexpensive in my area. Regular gas at its peak was only $2.60/gal!

Did I make a reasonable choice for a car purchase at the time? What car would you have opted for?

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Money Looks Better In Your Bank Than Your Garage

While the statement is a bash on impractical fancy cars that make your garage look pretty, you can substitute in any money-draining hobby, object, or recurring expense. I am not opposed to enjoying our hard earned dollars–we’ve worked long and hard enough–but it is always a good idea to reassess our desires with reality and practicality.

I once had a medical school classmate who asked me why I would ever need to buy a skillet. It was evident that she never cooked anything her entire life. Fast forward 6 months and I noticed that her closet had at least 100 different pairs of designer shoes! Despite the seemingly outrageous expenditures she had, it was clear to me that she was financially set for life. Not from savvy financial sense, but from inheritance money. Thomas Stanley calls this “economic outpatient care”, which is fine as long as the income channel never runs out. Hey, 10 years later, it really hasn’t stopped and she became an anesthesiologist (although I’m not sure if she still works).

The people who actually run into financial trouble are those whose expenditures ramp up as their earning potential increases. This applies to the majority of my doctor readership. We start out dirt poor, generate hundreds of thousands of dollars of negative net worth, and get slapped by insurance companies trying to restrict every single penny doctors deserve while bringing in a low 6-figure salary. Actually, M.B.A. grads follow a similar track, albeit at a more extreme level. I’ve met recent M.B.A. grads who managed to see 22 countries and build up elite airline status with multiple carriers all in a 2-year span during business school! Afterward, they join private equity firms and command salaries in the $300,000 starting range and up to $500,000 within a few years!  The advantage and dangers of such earning potential is that you can build up wealth quickly but can also lose it even more quickly.

If you don’t have a trust fund to fall back on, you have to play an active role in squashing out your debt and building your assets…no matter how big your paycheck is.

You Must Reassess Your Lifestyle Regularly.

Hold onto your receipts or review your credit card bills. Remind yourself what you are spending your hard earned dollars on.  Find out where your earnings are going towards and get angry at unnecessary expenses.  $2,000 a month restaurant bill? $800 heating bill in the winter? Routine last-minute cross-country airfares to visit friends? It doesn’t matter if you bring in $10,000 or $30,000 a month of income. If the expenses aren’t justified or sustainable, cut them out. I am relatively cost conscious but still find myself susceptible to lifestyle creep.

Since I rarely use cash for purchases, I track my expenses using Personal Capital. You can link up your bank and credit accounts to one system and categorize your I/O’s of your finance. Each week I can pull up a chart showing where my income and expenses were directed. They also provide a robo-investment/advisory service at relatively low costs (that is how they make money), but I currently only use the online financial information services. My investments are also categorized and I can quickly assess how much tilt or where my funds need to be rebalanced.

Direct Your Earnings Towards Your Bank

Every time you receive a raise or paycheck, be sure to pay yourself first. This means allocating a fixed amount or percentage of your income towards retirement and investments. Set realistic savings goals that are achievable. I currently allocate 50% of my post-tax income towards savings. Is that sufficient? Yes, but as high income earners who are able to control our expenses, it is conceivable to save up to 70-90% of our income!

Your savings goals will depend on your short and long term plans. Do you wish to reach FIRE? At what age? Do you have kids that you have to put through an Ivy League education? Do you want to be a millionaire or a $5 millionaire? Do you plan to quit your medical practice after five years and start living out of an RV? It makes good financial sense to draft out 5 and 10 year plans (I admit that I have yet to put much in writing either because I haven’t decided if I will settle in my current city or move on). As long as you do have an approximate plan and savings mechanism, you are much better off than the majority of our peers.


It is okay to spend your hard earned cash, but it is also important to reassess your financial goals regularly.

What strategies have you implemented to build your nest egg?

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My car’s check engine light on! What do I do?

Check engine light onSometimes the simplest explanation is the answer, but the solution becomes obvious only after the fact. My check engine light turned on last week, and I sort of panicked. My car was relatively new with a good maintenance schedule—why is it flipping error codes on me?

For most passenger vehicles built after 1996, on-board diagnostics (OBD2) is able to produce error codes that help you troubleshoot your vehicle. There is a serial port-like output often on the lower left side of the steering wheel where you can plug in the scanner. An OBD2 scanner can be purchased for less than $30 on Amazon.com for self-troubleshooting. If you go to your local AutoZone, O’Reillys, or your local dealer, they will have the device to scan your vehicle.

Common causes for check engine light include:

  • Gas cap loose – A loose gas cap on a modern vehicle will flip the check engine light. The gas tank belongs to a complex system that allows your car to remove and dispose of vapors in the tank. ACGO has a great overview of this system.
  • The oxygen sensor needs to be replaced. The sensor detects the amount of unburned oxygen in your exhaust. If it malfunctions, you can still drive your car, but the fuel economy will likely decrease.
  • Other items upstream of the oxygen sensor: spark plugs, air flow sensor, catalytic converter.
  • Evaporative vacuum hose leak.
  • Not so common: if you’re messing with your car alarm system or recently installed an aftermarket remote starter kit, you might want to check your wires.

In any case, most of these faulty devices will cost you hundreds (thousands if your dealer rips you off) to replace.

Fortunately for me, my fuel cap was loose:

Subaru gas cap
Tighten your gas cap or your check engine light will turn on!

The cap actually has printed instructions to tighten it!

If you have any questions or comments, sound out below! Any car problems to troubleshoot? Sound out below!

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Hidden benefits of washing your own car

wash your own carDIY tasks can save you a good deal of money, especially for many trade tasks like plumbing, carpentry, or basic handiwork. Previously we’ve discussed several DIY tasks for your car:

Some of you doctors out there will argue that you have better use of your time than to repair your car, or that “it’s too risky for my career to be fixing a car”. Yes, the previous articles discuss low-risk tasks that are high-yield. How about something even easier, like washing your own car?

Better yet, what do you think of washing AND waxing your car?

The technical and hardware requirement to wash a car is incredibly low. You’d need an outdoor faucet, which I’d imagine more homeowners or even renters probably have access to. A water hose would cost maybe $15 new (or less used), a $1 water bucket, a fancy $3 spray handle, a $1 sponge, a $5 bottle of super fancy car wash solution (should last 100 washes), and maybe a microfiber towel ($5) for drying the car. If you want to wax your car (you should), spend an extra $10 for nice TurtleWax. That adds up to less than $40 for all the equipment you’d need to wash and wax your car.

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If you take your car to the carwash, you will spend at least $5 for each wash (maybe closer to $8+ for nicer washes). The last time I checked out the cost of hand waxing a car was $50!

This means that after ONE car wash/wax job, you’d recoup the cost of your supplies!

Wait a second, buddy! As a general surgeon, I’m making $150 an hour! Washing and waxing my car would take an hour of my time! I’m actually losing money by washing my own car.

That’s absolutely true if you’d rather be doing an emergency appendectomy on a weekend rather than washing your car. It’s also true if there is an emergency for you to perform. This doesn’t even take into account the stress and liability that you incur in your profession.

Aside from the financial benefits of washing your car, there are health benefits. Hand waxing a car is not easy. Forearm muscles are used, and I burned at least 200 calories for an hour of work (use your favorite calorie tracking device to confirm). This free exercise that not only saves you money but also makes you healthier!

Questions? Sound out below!