Fuel Economy Question

[AZRedhawk44]

Changed the oil in my truck a couple weeks ago.  Been through about a tank and a half of gas since then.

Mileage is better on this oil change than it has been in maybe 2 years, by about half a mile per gallon.

The only thing I've done different is use a K&N oil filter instead of a Fram ToughGuard.  Can a higher quality oil filter improve fuel economy?

I usually pick up a Fram ToughGuard, a MOPAR, or a Pennzoil filter since I change the filter with the oil, like clockwork, every ~3500 miles.  I've used the K&N oil filters in the past a few times just as an experiment and I didn't notice anything particularly fancy about them back then.

I usually see about an 0.2mpg bump after an oil change... not an 0.5mpg bump.

Truck has 100k miles on it.

[charby]

How many miles on your truck? Usually once and engine is full broke in around 30k miles the fuel economy goes up slightly.

I run 0-30w Mobil One in my truck and I have noticed a slight fuel gain since I switched from synth blend to full synthetic. I have noticed that the truck was much easier to star this winter than last winter.

[Jamisjockey]

It's quite possibly the K&N. That reminds me, I need to get one in my truck. 
When I had my jeep cheorkee, I ran one in it and got a 2mpg bump highway, about .5 heavy city driving.

[AZRedhawk44]

3500 miles @ 17.5mpg = 200 gallons of gas, @ $3.50/gal = $700

3500 miles @ 17.0mpg = 205.9 gallons of gas, @ $3.50/gal = $720.58


If the mileage gain holds up, this filter is earning it's added $5-$7 cost over an inexpensive filter.  Probably saving the engine some grief in the long-run, too.

[Brad Johnson]

  Probably saving the engine some grief in the long-run, too.

Not quite.  It flows better because it filters less.  If you live in an area with lots of fine, silty dust, a K&N is a death sentence.  It will trap sand and other debris, but not powdery stuff.  My brother bought one for his Dodge (Cummins).  It seemed to run a little better and the reusability was appealing, but the first time we took it off for servicing the inside of the intake was covered in dust.  Paper filter back on, no more dust.

I might use one for purely highway use in someplace where blowing dust in places where blowing or fine dust is not a problem, but not around here.  Ever.

You're better off changing to a pure synthetics all the way through the driveline.  It will have about the same effect on economy with an additional bonus of extending the service life for other components.

Brad

[PTK]

Not quite.  It flows better because it filters less.  If you live in an area with lots of fine, silty dust, a K&N is a death sentence.  It will trap sand and other debris, but not powdery stuff.  My brother bought one for his Dodge (Cummins).  It seemed to run a little better and the reusability was appealing, but the first time we took it off for servicing the inside of the intake was covered in dust.  Paper filter back on, no more dust.

I might use one for purely highway use in someplace where blowing dust in places where blowing or fine dust is not a problem, but not around here.  Ever.

You're better off changing to a pure synthetics all the way through the driveline.  It will have about the same effect on economy with an additional bonus of extending the service life for other components.

Brad

Oil filter, not air filter.

[Brad Johnson]

Sorry, should have made it clear I was responding to Charby and Jamis about the K&N air filter.

No, an oil filter will not cause a 0.5 mpg bump in economy.  Changing oil, however, might.  Especially if you switch to a different viscosity.

Brad

[Jamisjockey]

Oil filter, not air filter.

 

I read K&N and thought air filter, too.

Brad's right about the dust, though.  I almost forgot about that.  Used to carry an air filter on off road trips and swap it out if I was going to be driving alot of dirt roads.

[zxcvbob]

Changed the oil in my truck a couple weeks ago.  Been through about a tank and a half of gas since then.

Mileage is better on this oil change than it has been in maybe 2 years, by about half a mile per gallon.

The only thing I've done different is use a K&N oil filter instead of a Fram ToughGuard.  Can a higher quality oil filter improve fuel economy?

I usually pick up a Fram ToughGuard, a MOPAR, or a Pennzoil filter since I change the filter with the oil, like clockwork, every ~3500 miles.  I've used the K&N oil filters in the past a few times just as an experiment and I didn't notice anything particularly fancy about them back then.

I usually see about an 0.2mpg bump after an oil change... not an 0.5mpg bump.

Truck has 100k miles on it.

Maybe they just switched from winter gasoline blend to summer where you are.  That makes a huge difference every year up here in Minnesota.  May not be as drastic farther south.

[Brad Johnson]

Good point.  The summer blends in the southwest are formulated for lower volatility in extreme (100+) temps.  That raises the actual octane rating a few tenths of a point over the crappy high-volitility winter blends.  Computerized engine management systems can take advantage of that by dialing up the timing a bit.  That can easily result in a few tenths of an mpg difference.

Brad

[Hawkmoon]

I second the opinion that the better mileage is due to "summer" fuel rather than "winter" fuel.

But that doesn't mean you can use a Fram filter next time. On the Jeep forum where I hang out, it has been documented by multiple forum members that Fram oil filters are death personified for engines. We've had innumerable newbies ask about various horrible-sounding problems with their engines. Any time discussion reveals that they just installed a Fram oil filter, we tell them to switch to a Purolator. 99.73% of the time the problem goes away.

Friends don't let friends use Fram oil filters.

[Brad Johnson]

Nothing really wrong with Fram filters.  There's only a billion of them motoring happily around as we speak.  If they were that inherently bad Fram would have been out of business years ago from lawsuits.

However...

Not to say that there isn't a better filter.  Purolator is one.  I think NAPA Gold is also one of the better units.  In reality, though, the only real difference is slightly better materials in the filtering media and silicon vs rubber or paper anti-drainback valves.  There's always the ultra-premium option of something like the Royal Purple filters, but they are a bit of overkill in my opinion. Not to say they aren't built like tanks, and with very high quality materials.  They are.  They're just a lot over-the-top unless you have tens of thousands invested in a one-off custom engine and want the Nth degree of protection.  It's kinda like hiring Brinks Security to guard the $99 Wal-Mart bench on your front porch.  It'll work, and work well, but it's a bit... much.

[brimic]

Maybe they just switched from winter gasoline blend to summer where you are.

Most likely cause.

I try not to overthink oil or filters. Change them on a regular schedule. I've run several cars over the 200K mark by simply changing the oil and filter every 3000 miles at the local quicky lube place. Synthetics might be better, but I have yet to wear out an engine on dino oil before the rest of the vehicle had fallen apart (other than a POS 1980s ford, that wasn't put together very well to begin with).

[sanglant]

there's one great big thing wrong with fram(etc.) air filters. if you have a car that specs oiled filters and the replacement isn't, you'll find the idle rough, and your mileage dropped. i was getting 23MPG instead of ~28-30 because of the things.

wait, looks like they've started making some oiled filters now. to late, already bought the K&N.

[Brad Johnson]

What current production vehicle specs an oiled-element air filter from the factory?  For the life of me I can't think of a single one except for maybe something offroad.

Brad

[sanglant]

for a start, every subaru.

[Boomhauer]

Nothing really wrong with Fram filters.  There's only a billion of them motoring happily around as we speak.  If they were that inherently bad Fram would have been out of business years ago from lawsuits.

However...

Not to say that there isn't a better filter.  Purolator is one.  I think NAPA Gold is also one of the better units.  In reality, though, the only real difference is slightly better materials in the filtering media and silicon vs rubber or paper anti-drainback valves.  There's always the ultra-premium option of something like the Royal Purple filters, but they are a bit of overkill in my opinion. Not to say they aren't built like tanks, and with very high quality materials.  They are.  They're just a lot over-the-top unless you have tens of thousands invested in a one-off custom engine and want the Nth degree of protection.  It's kinda like hiring Brinks Security to guard the $99 Wal-Mart bench on your front porch.  It'll work, and work well, but it's a bit... much.

Main reason I use a K&N is that big nut on the end means that it's quick and easy to wrench off rather than futzing with the stupid oil filter wrench. It's a feature that is standard on GA airplane oil filter canisters.

[drewtam]

I kid you not, there are Chinese companies that will put a roll of paper towels in a steel case and call it an oil filter. The owners don't understand or don't care. I am not aware of that junk making its way over here.


The final word on how often to change oil, what quality of filter to use, and what quality of oil to use comes from the oil sample itself. Take oil sample with fresh oil change, and at regular intervals in the cycle. The wear metals and soot/dirt loading will tell the story of how often you really need to change it. The dirt (silicates, etc) loading will also tell how well the air filter is doing its job.

These samples will tell the truth and no hype can change the results. Because your individual vehicle is different from everyone else. The engine design, its tolerance stack up, your driving habits, the fuel you buy, your environment, these all change how fast the oil degrades. In many cases, it tells people that they can safely go on much longer oil intervals without any damage/wear to the engine.

[Boomhauer]

I kid you not, there are Chinese companies that will put a roll of paper towels in a steel case and call it an oil filter. The owners don't understand or don't care. I am not aware of that junk making its way over here.


The final word on how often to change oil, what quality of filter to use, and what quality of oil to use comes from the oil sample itself. Take oil sample with fresh oil change, and at regular intervals in the cycle. The wear metals and soot/dirt loading will tell the story of how often you really need to change it. The dirt (silicates, etc) loading will also tell how well the air filter is doing its job.

These samples will tell the truth and no hype can change the results. Because your individual vehicle is different from everyone else. The engine design, its tolerance stack up, your driving habits, the fuel you buy, your environment, these all change how fast the oil degrades. In many cases, it tells people that they can safely go on much longer oil intervals without any damage/wear to the engine.

I'm still going to continue to change mine every 3K. Oil cheap. Engine not. Takes me 15 minutes. I grease the steering every other oil change.

[brimic]

I'm still going to continue to change mine every 3K. Oil cheap. Engine not. Takes me 15 minutes. I grease the steering every other oil change.

Yes. I've argued with a 'lean' consultant/trainer/charlatan who was training our company in lean manufacturing about this. He claimed that changing oil every 3000 miles was a waste of time and money and that it only needed to be done every 10,000 miles. I told him that would work fine if you are only keeping the car for 30,000 miles or are buying an old beater to wear out. Probably the same philosophy he had towards manufacturing- run everything as fast and as often as possible- if it breaks, figure out why

[Brad Johnson]

for a start, every subaru.

Well, they always were a little off...

*ETA*
By the way, your reply of "every Subaru" struck me as odd, what in this day of replaceable conveniences and over-zealous liability attorneys just waiting for Big Car to make even a single misstep.  If I were a vehicle mfg I wouldn't want the liability of a regularly serviced part so maintenance intensive as an oiled element air filter.  That is, except on some dedicated performance models where the owners would likely know how to care for them properly.  So I looked.  I found lots of stuff on the web about Subaru air filters.  I only found a few references to an oil-element filter.  Very few.  So I challenge your assertion that every Subaru has an oiled element air filter.  From what I can see all but one or two performance models have a garden variety replaceable paper element.

Brad

[Brad Johnson]

Yes. I've argued with a 'lean' consultant/trainer/charlatan who was training our company in lean manufacturing about this. He claimed that changing oil every 3000 miles was a waste of time and money and that it only needed to be done every 10,000 miles. I told him that would work fine if you are only keeping the car for 30,000 miles or are buying an old beater to wear out. Probably the same philosophy he had towards manufacturing- run everything as fast and as often as possible- if it breaks, figure out why

If you really want to get technical about it, you change the FILTER every 3000-8000 miles, depending on driving style, and change the oil when a used oil analysis shows a need for it.  Some full synthetics regularly exceed 20k miles before the additive package has broken down enough to need refreshing.

Head over to BobIsTheOilGuy.com and check it out.  Very informative.

Brad

[brimic]

If you really want to get technical about it, you change the FILTER every 3000-8000 miles, depending on driving style, and change the oil when a used oil analysis shows a need for it.  Some full synthetics regularly exceed 20k miles before the additive package has broken down enough to need refreshing.

Head over to BobIsTheOilGuy.com and check it out.  Very informative.

I get that. He was trying to tell me that dino oil didn't need to be changed anymore than every 10,000 miles

[Brad Johnson]

I suppose if you putter around in a moderate climate, never doing anything more stressful to your vehicle than going to the corner store, you might be able to get away with 10k on modern group III extended life oils.  Wouldn't recommend it though.

Brad

[seeker_two]

I change my truck's oil every 3000-5000 miles with standard 5w-30 dino oil. Air filter is changed every 3 oil changes and blown clean with compressed air every oil change. I change the fuel filter every six oil changes. And I use RXP ( http://www.rxp.com/master.htm ) every other oil change.

In the last four vehicles I've owned, I haven't had a single oil, fuel, or air-related problem.