All Wheel Drive Auto: Independent Seattle Subaru Service


Subaru Service Seattle; Subaru Fuel Economy Tips & how to decrease its energy use

I started this blog post by looking through some of the older articles I have posted about fuel economy and it’s interesting to take a look back and read some of my thoughts as well as comments from readers.  

I think we can all agree on one thing: Paying 50 cents + a gallon more for the same thing you did a couple weeks prior is never a welcomed event. That is where we find ourselves however to begin the year 2022.  This time it has occurred so fast there has not been ample time to adjust to it. 

We have had several notices from suppliers and vendors that we are about to experience a price increase on top of the ones we just absorbed. What that means is the gas prices of today are going to affect the cost of anything and everything that uses fuel to be accomplished in the immediate future.

It takes energy to move the world to where it wants to go, or to supply what it needs where it needs it. While this post is about trying to improve fuel economy, that’s also about decreasing the amount of energy needed to perform a task, or a trip and I think thats just a better way of thinking about this.

Subaru has just started making their first EV and while I have not seen one out in the wild yet, I have talked to enough people whose opinions I trust to know that it’s a good first entry, but the fact that the first year production is capped at less than 7000 units (and they are all accounted for) means if your a Subaru owner looking to change to electric and stay with the brand, 2022 is not going to be the year it happens for most of us.  I will also add that at this time an EV may not be the right answer for many drivers and if you are considering one please do all of your homework.

So with that said and this website being geared towards Subaru ownership help and information, let’s talk about things you can do right now with the Subaru you own to lower some of its energy use.

Now I do not want anyone reading this to think I am somehow suggesting ways for taking your 1996 Outback (which if an Automatic) may only achieve the high teens for economy and transform it into a modern CVT equipped Impreza obtaining 30+ MPGs or taking that Modern Impreza and giving it Prius like numbers. No, this is a post about maintaining or improving back to as advertised.

It all starts with how your Subaru tracks down the Road

  1. Tires, One of the single largest contributors to lower than desired fuel economy, (I am talking about economy less than what Subaru tested it to be) is rolling resistance.  If a tire is underinflated the rolling resistance increases which takes more energy to accomplish the same task of getting the vehicle up to speed. Simply making sure your tires are property inflated costs you no money at all and can save you hundreds over the entire span of ownership. If you have ever used a wheelbarrow, hand truck or a bicycle with a low tire I think you can relate to how much more energy it takes to get the same task done
  2. Alignment,  Now that we have the tires inflated to the proper PSI let’s talk about how those tires are pointing. This is referred to as an Alignment and is often one of the most overlooked aspects of vehicle ownership in my opinion. If the tires or vehicle is out of alignment it can affect how the car tracks down the road as again the amount of rolling resistance is increased requiring more energy to get you to where you are going. If you have ever skied cross country you know that two skis pointing in the same direction is way easier than when the one or both of the skis are pointing in or out. Shops like ours offer to do free alignment checks while you’re in for other service and yes once a car has aged a bit it’s going to find itself out of alignment more often as the steering and suspension systems age.  After year 3 it’s my suggestion to have the alignment checked every year and performed as needed.  Also if there is an event such as hitting a curb, or driving through a large pothole, something if you live in or around Seattle you know is commonplace.  I will add that a properly aligned Subaru is also the safest one you can own.
  3. Vehicle maintenance with a concentration on fluids.  This is one thing I still feel is largely deceptive on the owner’s manual and it’s not just Subaru it’s all of them, but again this is a site about Subarus so I digress. I will start with the engine, engine oil is there to lubricate and cool the engine parts. Modern vehicles use a very light grade of oil as in the case of modern non Turbocharged Subarus utilizing 0-20.  The use of a grade of oil such as 0W20 over say 5W30 increases the engine’s efficiency by lowering the rotating mass drag also known as friction. Now making sure that oil is in good condition is also crucial to the economy and overall health of the engine. The amount of things that happen in a modern car around oil that’s less than desirable all contribute to more energy use, oil that doesn’t cool as well as it did 5000 miles ago causes the cooling fans to come on more often as an example, the alternator will put more load on the engine to power the fans and while yes this is very incremental but over 5 years of ownership adds up to more more fuel usage and more wear on the alternator and primary electrical system.  Automatic transmission fluid or also now known to many as CVT fluid can overtime collect small particles from normal internal transmission component wear, and again over time may not be as effective and maintain transmission efficiency.  Manual transmissions and front and rear differentials in a Subaru use gear oil which is thick nasty stuff that loves to collect moisture. While most Subaru’s call for GL5 this is one place that I believe upgrading to Synthetic fluid is not a bad idea.     
  4. AC system (if Equipped).  Whether you live in triple digit heat in the Summer or negative digits in the Winter the AC system in your Subaru is all about your comfort in the Summer and your safety in the Winter. Just like using an Ac system in a house is going to cause the meter to spin, it has the same effect in your Subaru. The extra load on the engine requires more energy and your current Subaru uses fuel to create it. In the winter months anytime the system is set to defrost the AC compressor comes on and the heat created by the pressure cycle is used to dry the moisture off of the inside of the windshield. This also decreases the amount of time a frozen windshield takes to “defrost” , also decreasing the amount of time the engine must be running to achieve this. If your AC system is not functioning at its peak it will need to run longer to cool the cabin in the Summer, run longer in the Winter to defrost, the longer it runs the greater the load on the engine over time will be.   I will add here that a restricted cabin filter on a modern system will also mean the system runs longer to cool the cabin area down 
  5. Tune related issues.  This is spark plugs, air filters, PCV, fuel injectors, and any carbon deposits that have accumulated to the valves, pistons or any other area of the combustion chamber.  These items really need to be replaced on the proper schedule, inspected periodically and replaced and or serviced as needed in between.  If you own a modern Direct injection Subaru the efficiency of the system has the drawback that if not driven fairly hard the amount of carbon that can and will collect requires something called a Walnut blast to correct.  This is nothing new to many owners of European vehicles but it is something that Subaru owners of direct injection equipped models are slowly starting to discover.

Now there are other little things that can be done to save fuel such as shutting the Subaru off rather than letting it idle at the light, but I will also point out that wear to the starter will increase as will alternator load as it replaces the energy used by the battery to engage the starter.  Modern vehicles with the start stop feature have a monitoring system in place and will not kill the vehicle at a stop light if it picks up any deficiency in the primary electrical system. You could be in for a surprise in an older Subaru at an intersection if you have ignored or were unaware of a slow crank situation for example.

You can shut the car off while coasting down a hill, or on the downward side of a mountain pass.  As a child of the 1970s I remember my father doing this very thing in our Audi Wagon because we had no money growing up and gas was very expensive, I also remember it not always starting because it was also a 1970’s Audi Wagon, but it was a manual so he would just compression start it.  So this is actually one I do not recommend at all in a modern Subaru.  Let’s just forget I mentioned it.  

In closing I just want to point out the following, it takes energy to move around or “travel”, and well energy is just not free. In humans. It’s called calories, it takes calories to sustain us the more we do, the more we need. At some point in time we started riding horses to get around as it was a more efficient way of getting somewhere this method of travel also involved burning calories and a horse plus whatever apparatus you used with the horse, doesn’t matter if it was a a saddle or a wagon, it cost money and required maintenance.

Then came the car and the Internal Combustion Engine also known as the ICE.  We have spent decades upon decades making the ICE as efficient as we can and there’s actually more that can be done but as we appear to be on this trajectory towards EVs I just want to point out that the energy they use is just a different form of energy.  Items 1, 2 and most of 4 on my list will mean the same on an EV as they do to an ICE if you want to maintain or improve efficiency.  

Now I am not suggesting you immediately call to schedule a 60k service, Alignment and AC service, what I am letting you know however is that if your Subaru needs these things it will be better for your Subaru and has the added benefit of maintaining its economy. My advice is to do things as your budget allows, don’t panic or emotionally spend money trying to achieve better than possible, instead just get caught up and or continue to maintain.    


Thanks for Reading 




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