I drive a 2003 crv with 218.556 km on its clock. I usually get around 9 kpl on highway at 80 kph but recently, i was averaging around 5.6 kpl on a 50 km trip running at an average of 70 kph. Btw, im changing my engine oil at 219.000 km, does old engine oil affects fuel consumption??

Any tips or suggestions? Thanks

  • 2
    Welcome to the site. Asking "Any tips or suggestions" is rather broad and will probably get lots of opinion responses. Tell us what you have attempted to resolve this. For instance, when was the last time the engine had a complete service (tune up)?
    – CharlieRB
    Jun 5 '17 at 15:10
  • 2
    That's quite a change. Old oil can affect fuel consumption, but not by that much. With that many kilometers, it's probably time to replace a lot of things. Check your manual for any scheduled maintenance items (spark plugs, coolant, etc.).
    – Spivonious
    Jun 5 '17 at 15:36
  • It may also be worth your time to check out some of the other questions tagged under "fuel consumption" on the site. Without more details about the vehicle and its service history, anything we say is going to be a shot in the dark.
    – Zshoulders
    Jun 5 '17 at 20:15
  • VTC as OP has not added sufficient information to properly diagnose anything. Jun 6 '17 at 17:36
  • It never undergo a tune up since it is silky smooth when in idle. Ive changed the spark plugs, new engine oil. Still the same results. Theres no check engine lights on.
    – Vin
    Jun 29 '17 at 16:34

I wouldn't expect to notice a change in fuel consumption between oil changes, much less the 60% increase described.

First, 50 km is not a very long trip; the difference between 9 k/l and 5.6 k/l is only like 3 l. Are you sure your fuel consumption measurement is accurate?

Next, was there anything different about this recent trip that may have caused an increase in fuel consumption? For example, hilly terrain, A/C on, lots of idling, extra weight in the vehicle, carrying something on the roof, parking brake engaged, towing a trailer...

If not, check for leaks: inspect fuel lines (with fuel pump running), fuel tank after filling up, etc. Often you can detect a fuel odor after driving.

Could be any number of things, or a combination. Things like extra rolling resistance: Low tire pressure or a dragging brake. Or less common things like a slipping clutch or automatic transmission.

Time for a tune-up, maybe?

  • I can smell fuel odor after every trip. Is this normal bc i have a new car (chevy sonic) that does the same.
    – Vin
    Jun 29 '17 at 16:36
  • 1
    No, it's not normal to smell fuel. Fuel systems have been sealed since the early 70's. I would check for leaks. The tank, filler, fuel lines, hoses, etc. Check for leaks with the fuel pump running
    – user28910
    Jun 30 '17 at 14:32
  • 1
    We checked for leaks under the car, in the injectors and in the fuel line. Still, there were no leaks.
    – Vin
    Jul 2 '17 at 7:36

Engine oil can have an affect on fuel consumption yes. The components in the engine require oil to run as efficiently as possible. Fresh oil allows the components to move freely, as it reduces the amount of friction these components can experience (as tolerances are so tight).

Over time though the oil degrades. The oil loses it's ability to lubricate efficiently, meaning friction isn't being reduced as effectively as it once was. This means the components are finding it harder to move, and in turn require more power to move against the increase in friction.


I get around 3.3 KMPL 2.0 JDM iVtec 160 BHP. I've got a short Ram intake, high performance coils, fast fuel injectors and iridium coated plugs and a super tight serpentine belt with more traction on both sides. New high endurance pulleys, water pump, belt tensioner, and I've removed all obstacles that can effect cooling the condenser and radiatior. Oh and I changed the complete AC system. I don't drive less that 6000 RPM on average.

Now here's what you're looking for, less fuel economy, mate just check for your air filter. Majority of the time it's driving style and air intake that does the most harm here.

2003 crv was know for petrol leaking issues. You may have a leak. Your engine chain and tensioner has to be upgraded at this point. Valve clearance has to be set right. Water pump, steering pump, all pulleys, serpentine belt, alternator, battery and terminals, along with an automatic serpentine belt tensioner. Get your car on a scanner while idling and while on the road. Both times check what comes up. Even a bad catalytic converter or oxygen sensors can kill fuel economy.

  • Which grade fuel do you use? I use American 93 or Canadian 97ron. Anything else is less than factory specs. Jun 6 '17 at 8:05
  • 1
    I use ordinary unleaded fuel. There's only 2 inthe philippines unleaded and premium. I've put it in a scanner, there were no codes showing up. And its i can smell fuel odor after any trip
    – Vin
    Jun 29 '17 at 16:39
  • Is the fuel smell coming from the front left or rear left? Jun 29 '17 at 16:47
  • From the exhaust. Idk if its normal.
    – Vin
    Jul 1 '17 at 8:56
  • That is normal, but too much smell could indicate a cylinder throwing fuel into the exhaust system. Jul 1 '17 at 9:11

Your O2 sensor may be dirty so the engine gets an over rich mixture. Try using an additive like the Wynns lambda sensor cleaner in your fuel.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.