confusion on time vs mileage??
confusion on time vs mileage??
I am a bid confused when it comes to IE change oil every 3000 miles or 3 months, which ever comes first, or change your fuel filter every 30000 miles or better yet every year. Mind you Iam not arguing the point I am just sayingwouldn't it have something to do with how the car is used. What I mean is lets say I never drive my car less then 10 miles upon every start up, therefore moisture wouldn't collect in the oil, then why wouldn't you wait for the 3000 miles? What about the fuel filter, if you only drive it 7000 miles a year why would you change it vs waiting until lets say 15k?? These are just two examples of what I am asking, I guess what Iam asking is, are there exceptions to the rule IE 3000 miles or 3 months and anything else related to mileage or time?? Wayne
All fluids age with time, regardless of use.
Example, I've got a miata which is my "fun" car, it's used as my personal car and doesn't rack up nearly as many miles annually as the Q. Still, I change the oil every 3 months, even if it's only been driven 1000 miles. As the oil ages, the detergents begin to fail and the chemicals alter thier behavior. So all the combustion byproducts the detergents would have been collecting, began to become active again. The short trips cause a build-up of moisture, which can lead to rusting, etching, etc.
Gasoline can begin to varnish, leading to all kinds of problems for the fuel system, so changing the fuel filter is a good preventative measure along with keeping the tank stablized with an additive.
Brake Fluid is Hygroscopic, which means it tends to collect water over time, even if the system is "sealed" and that collected water will pool low in the calipers leading to rust. So I still flush them regularly.
I even change the radiator fluids annually, just in case.
It's good preventive routine which keeps the odds in your favor!
Example, I've got a miata which is my "fun" car, it's used as my personal car and doesn't rack up nearly as many miles annually as the Q. Still, I change the oil every 3 months, even if it's only been driven 1000 miles. As the oil ages, the detergents begin to fail and the chemicals alter thier behavior. So all the combustion byproducts the detergents would have been collecting, began to become active again. The short trips cause a build-up of moisture, which can lead to rusting, etching, etc.
Gasoline can begin to varnish, leading to all kinds of problems for the fuel system, so changing the fuel filter is a good preventative measure along with keeping the tank stablized with an additive.
Brake Fluid is Hygroscopic, which means it tends to collect water over time, even if the system is "sealed" and that collected water will pool low in the calipers leading to rust. So I still flush them regularly.
I even change the radiator fluids annually, just in case.
It's good preventive routine which keeps the odds in your favor!
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Q45tech
- Moderator
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- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Engine oils are tested for 65 hours [under highway load] to comply with SJ specifications:65 x 57.5 mph average speed = 3,750 miles where Infiniti gets its numbers. 65 hours around town might only be 2,000 miles but the heat/loads are lower [maybe?]........running car 1 hour per day is 90 hours in 90 days........might be 1800 miles or 5400 miles.
Most [99% maybe 99.9%] engines will survive the 70,000 mile warranty period with 7,500 mile/6 month change intervals. The question is how much wear has occurred ? Those of us that think an engine should survive and perform nearly as new [power] at 250,000 miles would be well advised to use the 90 day interval.
70 mph cruising uses maximal EGR so there is more exhaust dirt [carbon] getting into engine than in town driving..........if you drive 2,000 mile per month........you need an oil filter change every 2 months.
Synthetics subjected to the same 65 hour test generally don't change viscousity at half the rate allowing them to stay in longer BUT the wear is from the dirt in the oil [size of oil filter- capacity to hold dirt]............unfortunately the filter is sized for 3,750 miles WORTH.
The other problem is the particles to small to be trapped by filter which causes all the wear..........the only way to get them out is to drain the oil.
You just look at the oils color vs brand new on a white paper towel............when it darkens you change the oil. The more miles [more wear] the faster the oil changes color.
Air filters are critical in decreasing wear oem should be changed every year [some cheap and expensive aftermarkets might only last 6 months] if maximum life is desired.
As to air filters you just buy a half dozen from Scottsdale and change your own.
Rub your finger across the front of MAF protective screen ........where did all that black soot come from...........this stuff clumps together and forms big bad wear particles in your engine oil.
To pass the above the oil cannot increase viscosity more than 30% [ugh].
Most [99% maybe 99.9%] engines will survive the 70,000 mile warranty period with 7,500 mile/6 month change intervals. The question is how much wear has occurred ? Those of us that think an engine should survive and perform nearly as new [power] at 250,000 miles would be well advised to use the 90 day interval.
70 mph cruising uses maximal EGR so there is more exhaust dirt [carbon] getting into engine than in town driving..........if you drive 2,000 mile per month........you need an oil filter change every 2 months.
Synthetics subjected to the same 65 hour test generally don't change viscousity at half the rate allowing them to stay in longer BUT the wear is from the dirt in the oil [size of oil filter- capacity to hold dirt]............unfortunately the filter is sized for 3,750 miles WORTH.
The other problem is the particles to small to be trapped by filter which causes all the wear..........the only way to get them out is to drain the oil.
You just look at the oils color vs brand new on a white paper towel............when it darkens you change the oil. The more miles [more wear] the faster the oil changes color.
Air filters are critical in decreasing wear oem should be changed every year [some cheap and expensive aftermarkets might only last 6 months] if maximum life is desired.
As to air filters you just buy a half dozen from Scottsdale and change your own.
Rub your finger across the front of MAF protective screen ........where did all that black soot come from...........this stuff clumps together and forms big bad wear particles in your engine oil.
To pass the above the oil cannot increase viscosity more than 30% [ugh].