Can an oil filter kill MPG's by over 10%?

[dtlee]

I regularly get 65MPG overall in my car but recently, right after changing my oil to Mobil1 0w-20, I started getting 55MPG. Even driving on the freeway and being as conservative as I can, I cannot get the car to achieve the MPGs I was getting prior to oil change.

My father supplied me with the oil filter, and it's not Honda OEM. It's a Fram "Tuff Guard" and it's a noticeably shorter can than the blue honda filter. It's not a regular Fram, it's their "heavy duty" model. I would say it's a good 30% shorter. Could this affect my MPGs? My dad picked up the filter from the auto parts store.

My first thought was that I had a nail in my tire. Checked all pressures - all good.
My second thought was that I had overfilled the oil. Checked, and it's good. About 2mm from the top hole on the dipstick.

It's not particularly colder or windier in San Francisco this week. And I definitely have been driving as conservatively as I can trying to get my mileage back!

Could it be the filter???

[joecvt]

I don't think the oil filter would cause a change in MPG...If possible, it certainly would not be a 10MPG difference. Many times, it is the case of overfilling, Even though you checked the dipstick, did you wait a few minutes after the engine stopped and are you on a flat surface when checking to get an accurate measurement? The are lots of hills in San Francisco I guess a better question is: Precisely how many quarts did you add? It only requires 2.6 quarts of oil to reach the full mark.

JoeCVT = Just your average CVT owner

[dtlee]

Well, I checked the oil after the car had been sitting for a few minutes and it was just 2mm below the dot. Should I drain some more oil out so it's at the midpoint of those 2 dots? I added less than 3 qts, I think I have 500mL left in the final qt but I think that's because I drained the car on my driveway, which is sloped.

[Armin]

Originally Posted by dtlee

It's a Fram "Tuff Guard"

Is that the one with teflon particles in it? That could explain all sorts of BAD THINGS happening to the engine!

[bryankwalton]

Originally Posted by Armin

Is that the one with teflon particles in it? That could explain all sorts of BAD THINGS happening to the engine!

I might be mistaken, but I believe ALL the Fram filters have that teflon crap on them. Even worse, Purolator has very recently added this to there very highly regardled Pure One filters. And even worse, on the Pure One's it isn't on just the end -- but the ENTIRE THING! Personally, I'll stick to my Wix.

Photos of new Pure One with Teflon particles down inside the filter

[japanev1]

When I bought my CVT Insight it was getting around 54mpg which was consistent with the lifetime mpg rating. Within the first few weeks I changed the oil, oil filter, air filter(it had a fancy K&N 50,000 mile air filter which will require special hazmat disposal), and cabin air filter(not related to mpg) to 100% OEM Honda parts. I noticed an immediate jump to around 58mpg by changing the oil and air filters as well as much smoother running. I bought some OEM Honda CVT fluid, but after changing the oil she runs so smooth I may wait a few months before replacing the tranny fluid. Just a few weeks ago I ordered a set of new OEM Bridgestone tires to replace some wide Toyos that came on my Insight as well as some new brake pads. I only inflated them to 40psi and they quickly raised my trip mpg to 59.5 until I filled up a week ago. My current MPG after all "return to 100% stock" modifications has resulted in 66.5 trip MPG over 250 miles with the additional weight of an OEM trunk mat and cargo net, albeit the added weight is being offset by the warmer outside temps now. I'm starting to drive at 60mph on the highway instead of 70mph as I found 70mph cruising gets 50-55mpg, and 55-60mph gets 65-75mpg on a constant flat road, sometimes getting 100+mpg. My next tank I bet I can get 70+mpg with the CVT!

[james]

Why would a K&N filter require hazmat disposal? Indeed, why would it require disposal at all, when their big selling point is reusability? If you don't want it, list it on the for sale section as free for cost of shipping - I'd take it, if I hadn't already bought one.

[japanev1]

Originally Posted by james

Why would a K&N filter require hazmat disposal? Indeed, why would it require disposal at all, when their big selling point is reusability? If you don't want it, list it on the for sale section as free for cost of shipping - I'd take it, if I hadn't already bought one.

The sticker on the airbox that came with the K&N indicated something about special disposal required due to the oil and chemicals in the filter itself, not exactly sure as the sticker and filter are long gone now. The filter itself was dirty and my best friend who is a highly skilled mechanic and takes excellent care of my Insight (he is specially trained to work on hybrids and Evs) quickly ditched the K&N filter before installing a fresh OEM air filter that he had ordered directly from Honda. He is a strong believer in the OEM stock everything, after having to deal with the problems of after-market auto parts on a daily basis. His reasoning is that a lot more R&D goes into making all the stock parts as compared to after-market and he has seen K&N filters installed on diesel trucks actually dust the motor causing extensive damage. I'm not trying to poo on K&N filters, but I trust my mechanic when he says they are an avoidable hassle.

[bfivelover]

Originally Posted by james

Why would a K&N filter require hazmat disposal? Indeed, why would it require disposal at all, when their big selling point is reusability?

Exactly. But if you want to toss it, the oil on it is mineral and animal(Yuck), so I doubt it's to harmful.