Original Thought on Oil, Change Intervals, Fill Amounts, etc.
03-18-2003 | 08:51 PM
#1
Thread Starter
03 Accord Owner
Joined: Jan 2003
Posts: 111
Likes: 0
From: State College, PA
Original Thought on Oil, Change Intervals, Fill Amounts, etc.
OK - kinda dumb - but WHY do all cars take 5 qts. of oil.
Think about it - everyone says - or the oil co's do (not the service manuals always) to change the oil at 3K. OK - that's all well and good - but why do much smaller 4 cyl. engines still take 5 qts.? Why should they be changed as frequently as a 5.0 V8 Stang? You get the point of my question.
1 - Why similar intervals with less cyl. that would create deposits, thermal breakdown, etc.
2 - Why still 5 qts. per car?
Seems to be should have correct ratio for all cars for the qts. like 1 qt. per certain amount of Liters displacement, etc., --- if the engines were designed that way - and the same change interval - say every 5K .....
Just curious
(Someone brought up in my botched subject post about RPMs higher in smaller engined cars - I agree, but that's certainly not always the case at all. THere are plenty of high reving high displacement cars out there, and low reving 4 cyl. engines too.) Maybe it's just the oil companies going with a happy amount to fill their pockets better - more than likey the case - but still - you'd think there would be more talk about this amoungst car people - some koind of 'inside' pseudo-equation to figure out, while althoguh all engines are baiscally made the same in that they take 5 qts. of oil - you can 'calcular' how ofteen to change your oil and filter based on the following input:
Oil type (Dyno, Blend, or Synth.)
Oil viscosity
Filter size
Filter quality (NOT FRAM CRAP, hah)
Engine Displacement
Engine Red-line RPM
Boosted or not
etc.
I think it would be an awesome (but time consuming) project to seriously do a little research, hard reasearch, about oil break-down times, etc., etc., etc. - all the hard science iinvolved and come up for a rough 'beta' versoin of some type of oil calculator.
Then with the calculator you could figure out what is the best oil and filter combination for protection, what is best for your dollar, etc.
Input?
Think about it - everyone says - or the oil co's do (not the service manuals always) to change the oil at 3K. OK - that's all well and good - but why do much smaller 4 cyl. engines still take 5 qts.? Why should they be changed as frequently as a 5.0 V8 Stang? You get the point of my question.
1 - Why similar intervals with less cyl. that would create deposits, thermal breakdown, etc.
2 - Why still 5 qts. per car?
Seems to be should have correct ratio for all cars for the qts. like 1 qt. per certain amount of Liters displacement, etc., --- if the engines were designed that way - and the same change interval - say every 5K .....
Just curious
(Someone brought up in my botched subject post about RPMs higher in smaller engined cars - I agree, but that's certainly not always the case at all. THere are plenty of high reving high displacement cars out there, and low reving 4 cyl. engines too.) Maybe it's just the oil companies going with a happy amount to fill their pockets better - more than likey the case - but still - you'd think there would be more talk about this amoungst car people - some koind of 'inside' pseudo-equation to figure out, while althoguh all engines are baiscally made the same in that they take 5 qts. of oil - you can 'calcular' how ofteen to change your oil and filter based on the following input:
Oil type (Dyno, Blend, or Synth.)
Oil viscosity
Filter size
Filter quality (NOT FRAM CRAP, hah)
Engine Displacement
Engine Red-line RPM
Boosted or not
etc.
I think it would be an awesome (but time consuming) project to seriously do a little research, hard reasearch, about oil break-down times, etc., etc., etc. - all the hard science iinvolved and come up for a rough 'beta' versoin of some type of oil calculator.
Then with the calculator you could figure out what is the best oil and filter combination for protection, what is best for your dollar, etc.
Input?
03-19-2003 | 04:46 AM
#2
Cracker Quack!
Joined: Nov 1998
Posts: 659
Likes: 0
From: LI, NY
Not all motors take 5 qts... it really does vary from 3-8 qts depending on the motor....
In the end most people do the 3mo/3k intervals cuz nobody wants to learn longer intervals that would then be specific to each model of car and have to be relearned each time you changed cars.
noel
In the end most people do the 3mo/3k intervals cuz nobody wants to learn longer intervals that would then be specific to each model of car and have to be relearned each time you changed cars.
noel
03-19-2003 | 07:50 AM
#3
Senior Member
Joined: Jan 2003
Posts: 1,994
Likes: 2
Car companies have been messing with this. They've got enough $$ to waste a bunch of engines to figure it out.
More & more cars calculate oil drain times from more than just mileage. BMW started doing that in the '80s. My '01 Saab just uses miles and months. The new '03 Saab uses all kinds of stuff like calendar time, engine running time, # of revolutions (not miles), engine temperature, & number of engine starts. Dashboard computer can display remaining oil life in %%. People have said it can go as long as 20k. (For it to be valid you gotta use synthetic.) I'm too lazy to calculate all that stuff by hand...
I imagine US-EPA has even been pressuring carmakers for longer oil drain intervals, because they know lots of people still dump used oil on the ground... If not, there's some marketing pressure to have longer intervals, too.
If you really want to get into this, you can have used oil tested. Figure out a good interval for your car, your driving habits. But it won't be the same for other people & different cars.
More & more cars calculate oil drain times from more than just mileage. BMW started doing that in the '80s. My '01 Saab just uses miles and months. The new '03 Saab uses all kinds of stuff like calendar time, engine running time, # of revolutions (not miles), engine temperature, & number of engine starts. Dashboard computer can display remaining oil life in %%. People have said it can go as long as 20k. (For it to be valid you gotta use synthetic.) I'm too lazy to calculate all that stuff by hand...
I imagine US-EPA has even been pressuring carmakers for longer oil drain intervals, because they know lots of people still dump used oil on the ground... If not, there's some marketing pressure to have longer intervals, too.
If you really want to get into this, you can have used oil tested. Figure out a good interval for your car, your driving habits. But it won't be the same for other people & different cars.
03-19-2003 | 08:35 AM
#4
cx power!
Joined: Jun 2002
Posts: 2,435
Likes: 0
From: berkeley, ca --> la, ca representin' tha 510&626
I just follow the mfg's reccomendation and change my oil every 7500mi. However, I do use Mobil 1 10w30 with either an oem or mobil 1 filter.
Our family's mercedes has a "flexable service schedule" indicator, which counts down the miles to the next service, based on driving habits, milage, and time. It goes for about 10,000mi+ intervals on synthetic oil.
not all cars use 5qts. my accord uses 4.5 qt with a filter change. our old school 85 benz with a v8 uses 8qts. german cars usually have a remote filter, located just ahead of the cylinder block, accounting for some of the increased oil capacity.
Our family's mercedes has a "flexable service schedule" indicator, which counts down the miles to the next service, based on driving habits, milage, and time. It goes for about 10,000mi+ intervals on synthetic oil.
not all cars use 5qts. my accord uses 4.5 qt with a filter change. our old school 85 benz with a v8 uses 8qts. german cars usually have a remote filter, located just ahead of the cylinder block, accounting for some of the increased oil capacity.
03-19-2003 | 09:09 AM
#5
Thread Starter
03 Accord Owner
Joined: Jan 2003
Posts: 111
Likes: 0
From: State College, PA
Accords usually noly need 4.5 qts. cause about .5 qt still remains in the pan or engine. If we were about to 'shake upside down' our cars like an almost empty beer can, we'd be able to get most of the rest of the .5 qts. out. Accords are 5 qt. oil engines ....
But I do know that some caars take more than 5 qts. - but most are the 5.
I've seen a few cars with the approx. service indicator stuff - they are pretty neat - but I'd want to read the cars amnual that has it to see what all it takes into accont for oil changes, cause I wouldn't want to go too long before changing it just cause the car says so.
But I do know that some caars take more than 5 qts. - but most are the 5.
I've seen a few cars with the approx. service indicator stuff - they are pretty neat - but I'd want to read the cars amnual that has it to see what all it takes into accont for oil changes, cause I wouldn't want to go too long before changing it just cause the car says so.