Triple_Se7en
$50 Site Donor 2024
Judging by my 04' Colorado's 18 gal fuel fill-ups, that delivered roughly 300 miles and not grabbing a calculator or pencil for the correct math, I'm guessing that's somewhere around 9-10K OCIs.
Would changing oil by hour be better than miles?
- Thread starter mpgo4th
- Start date
- Status
I would tend to think going by amount of fuel through the motor would be best, but even that doesn't fully take into account load. Might come closest though. Hours may well be better than miles.
But it feels better to go by miles! Been doing that for years and years, too hard to give up that habit.
I don't have an hour meter in my car but it could be interesting if I had one. Maybe I should go cobble one up...
But it feels better to go by miles! Been doing that for years and years, too hard to give up that habit.
I don't have an hour meter in my car but it could be interesting if I had one. Maybe I should go cobble one up...
Of course the best is to service by UOA results.
Average speed divided by oci. I'd imagine most cars have an average speed tracker nowadays. That's how I figured out my last oci was 10,014 miles and 261 hours
Originally Posted by spasm3
I would think perhaps xxx gallons of fuel per oil change would be a better measure than hours. Not sure what that number would be, maybe 300 gallons of gas?
+1
Amount of fuel consumed automatically accounts for things like varying MPG due to different driving conditions (hwy vs city, extended idling, operating in cold environment, etc.). The OLM in my old 530i is based on amount of fuel consumed, although the actual amount they chose is a bit too generous, IMO. It's 627 gallons (2,375 liters) per OCI.
Some years ago, member TooSlick even came up with a formula to estimate OCI based on MPG (among other things). You can play around with it in this spreadsheet (see the third/last result):
https://docs.google.com/spreadsheet...2g2U0JwdGJPcVlwYmc&usp=sharing#gid=0
I would think perhaps xxx gallons of fuel per oil change would be a better measure than hours. Not sure what that number would be, maybe 300 gallons of gas?
+1
Amount of fuel consumed automatically accounts for things like varying MPG due to different driving conditions (hwy vs city, extended idling, operating in cold environment, etc.). The OLM in my old 530i is based on amount of fuel consumed, although the actual amount they chose is a bit too generous, IMO. It's 627 gallons (2,375 liters) per OCI.
Some years ago, member TooSlick even came up with a formula to estimate OCI based on MPG (among other things). You can play around with it in this spreadsheet (see the third/last result):
https://docs.google.com/spreadsheet...2g2U0JwdGJPcVlwYmc&usp=sharing#gid=0
Originally Posted by supton
I would tend to think going by amount of fuel through the motor would be best, but even that doesn't fully take into account load.
It kind of does because higher load = worse MPG = more fuel burned.
I would tend to think going by amount of fuel through the motor would be best, but even that doesn't fully take into account load.
It kind of does because higher load = worse MPG = more fuel burned.
Originally Posted by spasm3
I would think perhaps xxx gallons of fuel per oil change would be a better measure than hours. Not sure what that number would be, maybe 300 gallons of gas?
I'm with Spasm on this one. I'd probably go a little lower on the gallons of gas. Interesting to think about.
I would think perhaps xxx gallons of fuel per oil change would be a better measure than hours. Not sure what that number would be, maybe 300 gallons of gas?
I'm with Spasm on this one. I'd probably go a little lower on the gallons of gas. Interesting to think about.
Originally Posted by tiger862
My owners manual states 350 hours or 10k
Funny as I don't have a hour meter.
If you are talking about the vehicle in your sig, the engine hours is under the 'vehicle info' section of the instrument cluster.
My owners manual states 350 hours or 10k
Funny as I don't have a hour meter.
If you are talking about the vehicle in your sig, the engine hours is under the 'vehicle info' section of the instrument cluster.
Originally Posted by dave1251
It really depends on the operation of the vehicle. If the vehicle idles for 90% of it's operation time using mileage does not make sense.
Same if its doing long highway runs everyday. I have used 200 hrs for my vehicle which usually ends up around 7000 km combined. Though I tend to watch fuel economy etc around that time anyway and anything the dipstick can tell me.
It really depends on the operation of the vehicle. If the vehicle idles for 90% of it's operation time using mileage does not make sense.
Same if its doing long highway runs everyday. I have used 200 hrs for my vehicle which usually ends up around 7000 km combined. Though I tend to watch fuel economy etc around that time anyway and anything the dipstick can tell me.
Talk about making yourself nuts by debating the minutiae of maintenance.
The only time it makes sense to use hours on any automobile is when the vehicle has to spend a lot of time idling.
For most folks, basing your OCI on miles or date/time is fine. The few among us who don't drive very much or drive short distances should use date as a reminder, and it should always be based on the owner's manual recommendations. Not the oil change sticker that's put on your windshield.
There is no point in using gallons as a guide for an OCI unless you run a fleet, and even then it's fallible since the gallons consumed indicator can be reset by the user. Hours and odometer mileage can not be reset, which is why nearly every fleet maintenance operation uses one of these indicators.
Engineers spend their lives figuring out these parameters for a reason. Let's stick to the owner's manual and spend our strategic moments finding great deals on high quality oil and filters.
The only time it makes sense to use hours on any automobile is when the vehicle has to spend a lot of time idling.
For most folks, basing your OCI on miles or date/time is fine. The few among us who don't drive very much or drive short distances should use date as a reminder, and it should always be based on the owner's manual recommendations. Not the oil change sticker that's put on your windshield.
There is no point in using gallons as a guide for an OCI unless you run a fleet, and even then it's fallible since the gallons consumed indicator can be reset by the user. Hours and odometer mileage can not be reset, which is why nearly every fleet maintenance operation uses one of these indicators.
Engineers spend their lives figuring out these parameters for a reason. Let's stick to the owner's manual and spend our strategic moments finding great deals on high quality oil and filters.
Last edited:
Originally Posted by macarose
Talk about making yourself nuts by debating the minutiae of maintenance.
This is BITOG after all, isn't it.
Originally Posted by macarose
Engineers spend their lives figuring out these parameters for a reason.
And some of them chose to use fuel consumed to determine OCI.
Talk about making yourself nuts by debating the minutiae of maintenance.
This is BITOG after all, isn't it.
Originally Posted by macarose
Engineers spend their lives figuring out these parameters for a reason.
And some of them chose to use fuel consumed to determine OCI.
Originally Posted by newtoncd8
Originally Posted by tiger862
My owners manual states 350 hours or 10k
Funny as I don't have a hour meter.
If you are talking about the vehicle in your sig, the engine hours is under the 'vehicle info' section of the instrument cluster.
I don't have the advance screen. Mine does mpg, temp,speed and 2 trips.
I don't worry about it as per my dongle I average 11 mph so I will have 1100 mile oci if I went on 100 hrs. I do 5k or there about which would be 500 hrs. Maybe I need to shorten it to 3500 as per manual of 350 hrs. LOL
Originally Posted by tiger862
My owners manual states 350 hours or 10k
Funny as I don't have a hour meter.
If you are talking about the vehicle in your sig, the engine hours is under the 'vehicle info' section of the instrument cluster.
I don't have the advance screen. Mine does mpg, temp,speed and 2 trips.
I don't worry about it as per my dongle I average 11 mph so I will have 1100 mile oci if I went on 100 hrs. I do 5k or there about which would be 500 hrs. Maybe I need to shorten it to 3500 as per manual of 350 hrs. LOL
Last edited:
I do it somewhat. I change oil in both cars evry 6K km or about 150hrs of engine running time.
If one's car idles a lot or driven in heavy stop-and-go traffic very often then going by hours makes sense.
If one's car idles a lot or driven in heavy stop-and-go traffic very often then going by hours makes sense.
Using mileage intervals is obviously not the best method in every circumstance, but it's easy, and good enough, as long as the usage pattern is reasonably consistent, and typical of what vehicle manufacturers assume when they prescribe mileage intervals for oil changes.
It wouldn't be difficult for me, for example, to count gallons burned and change every 150 gallons, but tracking mileage is even easier, and my relevant habits (and mpg) are fairly consistent.
It wouldn't be difficult for me, for example, to count gallons burned and change every 150 gallons, but tracking mileage is even easier, and my relevant habits (and mpg) are fairly consistent.
Depending on usage patterns you could idle with PTO for 50 hours without moving one mile. One size does not fit all.
Large city mixed suburban driving - I change oil at approx. 150 hours (synthetic D1/Gen 2 oil) . This also equates close to 4K miles and an average speed over the oil fill of approx. 26 MPH ... *These three indicators (i.e. time , miles and average speed over the life of the oil fill) are my guide when to dump the oil .
Originally Posted by ChrisD46
Large city mixed suburban driving - I change oil at approx. 150 hours (synthetic D1/Gen 2 oil) . This also equates close to 4K miles and an average speed over the oil fill of approx. 26 MPH ... *These three indicators (i.e. time , miles and average speed over the life of the oil fill) are my guide when to dump the oil .
IMO hours is very accurate when you think about it. My average speed is a bit less than yours, and I often scratch my head when I hear blanket statements like a good dino oil can easily do 5K miles and a good synthetic oil can handle 10k miles with ease. Those claims might be safe for someone living in a rural area and they can hop on a highway and cover 50 miles or more in an hour of less, in traffic they might cover 40 miles in an hour. Simple math tells me if my average speed is 25 miles an hour my engine is running twice as long to cover the same 50 miles. That means in my vehicle dino oil is in the sump the equivalent of 10K miles for their 5K, and with a synthetic oil 20K miles time wise to cover their 10K miles. My average speed is less than 25 mph in two of my vehicles,making the numbers even worse. I've beaten this horse before, no thanks to a 10K oci for me at my current location.
Large city mixed suburban driving - I change oil at approx. 150 hours (synthetic D1/Gen 2 oil) . This also equates close to 4K miles and an average speed over the oil fill of approx. 26 MPH ... *These three indicators (i.e. time , miles and average speed over the life of the oil fill) are my guide when to dump the oil .
IMO hours is very accurate when you think about it. My average speed is a bit less than yours, and I often scratch my head when I hear blanket statements like a good dino oil can easily do 5K miles and a good synthetic oil can handle 10k miles with ease. Those claims might be safe for someone living in a rural area and they can hop on a highway and cover 50 miles or more in an hour of less, in traffic they might cover 40 miles in an hour. Simple math tells me if my average speed is 25 miles an hour my engine is running twice as long to cover the same 50 miles. That means in my vehicle dino oil is in the sump the equivalent of 10K miles for their 5K, and with a synthetic oil 20K miles time wise to cover their 10K miles. My average speed is less than 25 mph in two of my vehicles,making the numbers even worse. I've beaten this horse before, no thanks to a 10K oci for me at my current location.
+1
Originally Posted by demarpaint
Originally Posted by ChrisD46
Large city mixed suburban driving - I change oil at approx. 150 hours (synthetic D1/Gen 2 oil) . This also equates close to 4K miles and an average speed over the oil fill of approx. 26 MPH ... *These three indicators (i.e. time , miles and average speed over the life of the oil fill) are my guide when to dump the oil .
IMO hours is very accurate when you think about it. My average speed is a bit less than yours, and I often scratch my head when I hear blanket statements like a good dino oil can easily do 5K miles and a good synthetic oil can handle 10k miles with ease. Those claims might be safe for someone living in a rural area and they can hop on a highway and cover 50 miles or more in an hour of less, in traffic they might cover 40 miles in an hour. Simple math tells me if my average speed is 25 miles an hour my engine is running twice as long to cover the same 50 miles. That means in my vehicle dino oil is in the sump the equivalent of 10K miles for their 5K, and with a synthetic oil 20K miles time wise to cover their 10K miles. My average speed is less than 25 mph in two of my vehicles,making the numbers even worse. I've beaten this horse before, no thanks to a 10K oci for me at my current location.
Originally Posted by demarpaint
Originally Posted by ChrisD46
Large city mixed suburban driving - I change oil at approx. 150 hours (synthetic D1/Gen 2 oil) . This also equates close to 4K miles and an average speed over the oil fill of approx. 26 MPH ... *These three indicators (i.e. time , miles and average speed over the life of the oil fill) are my guide when to dump the oil .
IMO hours is very accurate when you think about it. My average speed is a bit less than yours, and I often scratch my head when I hear blanket statements like a good dino oil can easily do 5K miles and a good synthetic oil can handle 10k miles with ease. Those claims might be safe for someone living in a rural area and they can hop on a highway and cover 50 miles or more in an hour of less, in traffic they might cover 40 miles in an hour. Simple math tells me if my average speed is 25 miles an hour my engine is running twice as long to cover the same 50 miles. That means in my vehicle dino oil is in the sump the equivalent of 10K miles for their 5K, and with a synthetic oil 20K miles time wise to cover their 10K miles. My average speed is less than 25 mph in two of my vehicles,making the numbers even worse. I've beaten this horse before, no thanks to a 10K oci for me at my current location.
Last edited:
What got me asking this question it that my fleet has a bunch of new Freightliners in it. They all have cummins ISL 8.9L diesel engines. The Cummins manual that came with the trucks has a different maintenance schedule for each type of use. Mine would fall under severe. The sever use guidelines are to change oil and filter every 15k miles, 500 hours or 6 months, whichever comes first. For my use 500 hours usually comes first. After doing multiple UOA on my main trash truck the decision was made that the ideal OCI for this truck was 250 hours. Wear metal looks great at that time and soon after the oil starts to thin out of grade. On the other hand, the same truck with a different job duty always hits 6 months first. I wonder if anyone has had problems going with the 15k mile recommendation?
- Status
Similar threads
