When I bought my 2008 Honda CRV I was getting about 25mpg. Now I am only getting about 20mpg. I have the CRV serviced , tire rotation, oil changes on a regular basis.

What can I do to help my mpg?

Have you replaced the tires? Perhaps the new replacement tires have a higher rolling resistance than the OEM tires. Some tires really are much better than others in rolling resistance and the difference can be up to 4-5 mpg if you replace an efficient tire with an inefficient tire.

What have the temperatures been like in your neck of the woods recently?
If they have been very cold, it would be typical for your gas mileage to drop by a couple of mpg, due to the engine running on a richer fuel/air mixture prior to being fully warmed-up.

Do you warm-up the engine before driving?
Modern fuel-injected engines do not need to be warmed-up, and are ready to drive after just a few seconds. However, you do need to drive slowly and conservatively until the engine is fully warmed-up. If you sit and idle the engine for more than a few seconds, you are wasting gas and actually causing the engine to warm-up more slowly.

In the winter, many people rely on drive-up windows to a great extent, in order to stay in their nice warm car.
If you sit in a drive-up line at the bank, drug store, or fast food joint, this alone has a major negative impact on your gas mileage (and your waist line).

Do you do a lot of short-trip local driving?
Doing mostly short hops with your car in the winter will result in much lower gas mileage, simply because the engine is frequently running at less than full operating temperature.

Is “winter blend” gas used in your area?
If it is, this will reduce your gas mileage.

How often do you check (and correct) your tire pressure?
Tires lose approximately 1 lb of pressure for every 10 degree drop in temperature, and underinflated tires will reduce your gas mileage.

Having a vehicle serviced “regularly” means different things to different people.
Are you sure that the engine air filter is not in need of changing?
When were the spark plugs last replaced?
Are you sure that your mechanic is using the correct viscosity oil in your engine?

Additionally, it is possible that the cooling system thermostat is stuck in the open position, thus causing the engine to run too cool and to waste gas. While it is not likely that this would be a problem with a 5 year old car, it is not impossible.

Thanks for the info.

Plugs have never been changed. So I will check that out.

Also, I never thought of tire resistance so that is some good info.

How many miles on this buggy?
Also, based on time (5 years) if driven daily I recommend replacing the thermostat (and the coolant & radiator cap while you’re at it).

I have a similar problem that showed itself abruptly about 4 mth ago. The vehicle in question is a 2004 CRV, with 150 K miles now. MPG dropped from a consistent 25+ MPG (320 miles per tank) to a fairly consistent 20MPG (200-220 miles per tank). To complicate this, I did get a single tank that provided 300+ miles but that was a fluke. My regular shop gave up on me and a second mechanic is providing educated (and expensive) guesses. The “computer” fails to ID any problem and neither place knows what to do without it. I suppose if the wheel fell off but it didn’t show up on diagnostics… They have cleaned the injectors but no other real repair. Their thoughts are the catalytic converter! An $800 trial & error fix, unless I wait for a more complete blockage and failure that blinds me with the check engine light. Any thoughts??

Your boat is taking on water. If it’s a car, the four wheel alignment may be going off due to worn parts like tie rod ends.

Another unlikely scenario is that a knock sensor is detecting phantom knocks and is going bad or there is a real knocking noise that is making the sensor think that pre-ignition is happening. If there is any tapping noise from an accessory, the sensor might cause the computer to retard the timing and reduce the engine power and possibly the fuel economy too.

If you have pre-ignition due to carbon deposits that cause a hot spot to ignite the fuel, try running a tankful of premium gasoline. If fuel economy improves, you may want to use a can of Techron to help clean those deposits out.

I have a list of goofball events like a plastic bag that blocks an air filter but that probably has never happened in the history of the world part two.

How old is the thermostat?
It’s not expensive.
Get OEM, not aftermarket.

Your car is rated for 22MPG (4WD) or 23 MPG (2WD) overall. 20 MPG overall is in the ballpark, there’s probably nothing seriously wrong with your car.

It doesn’t sound like the mpg is a big concern, but (not including driving style) here’s what I’d do if I wanted to get the absolute best mpg I could squeeze out of my own car:

Every 12 months:

  • New spark plugs, fuel filter, and air filter.
  • Remove thermostat, put in pan of hot water, and verify opening temperature is correct.
  • Verify both coolant temp sensors meet specs.
  • Veryify EGR and PCV operations.
  • Verify ignition timing at idle.
  • Check compression.
  • Adjust valve clearance.
  • Check for exhaust leaks.
  • Test for exhaust obstructions, esp a partially clogged cat.
  • Have a mechanic do a real time check of the fuel/air mixture, either by an exhaust sniffer, or a fuel-trim measurement.

I’m not saying I do all this for my own cars, but if I wanted to squeeze every drop of mpg out of the car, that’s what I’d probably do.

@GeorgeSanJose, here’s a couple more:

  • check tire pressure every month, keep them ~4 psi over the door jamb pressure
  • take out the extra junk in the trunk
  • don’t idle to warm up the engine, except maybe 30 seconds if it’s below freezing.
  • don’t use the AC if you’re puttering around under 35mph
  • combine trips to minimize warm-ups
  • drive gently and a little slower

Good comments circuitsmith. I was thinking one other that is easy to do is switch to a high mpg oil that is compatible with the engine. Maybe a synthetic.