The 7,500 mile Oil Myth ?

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Why do so many late model owners manuals still show : 3,750 mile OCI for severe duty and 7,500 mile OCI for non - severe duty for vehicles WITHOUT an OLM ? It would appear that everyone living in the suburbs (majority of people) qualify for severe duty usage according to the owners manual !! There appears to be a disconnect in modern vehicle owners manuals and oil chemistry advances . Now throw in a synthetic oil into the equation which should go 7,500 miles easy - but then there is the severe duty statement (anything and everything qualifies for severe duty - unless driving 55mph in Montana ). For those who drive vehicles without an OLM you either follow the owners manual or get a oil test at Blackstone - basically your only two choices ?
 
Both my Toyota's came with 10k OCI's in the manual, as did my diesel TDi. The Camry I'm a bit leery, due to small sump; I should be the same on the Tundra, as it's not 2x the size. But, since I get nothing but highway, I don't worry about it.

IMO doing stuff every 10k is nice, easy to read off the spedometer. 5k is ok too. Easy to remember. Even if I had an OLM I'd probably default to doing it every 5k/10k--tires still need rotations.
 
Ive done 2 UOA on my camry and still shows plenty life left after 10k and wear metals are low. I do about 30-40% highway and the rest is 10 mile or less trips
 
Originally Posted By: ChrisD46
It would appear that everyone living in the suburbs (majority of people) qualify for severe duty usage according to the owners manual !!


because that simply is not the case. Case in point - my mother does five block commutes like six times a day. We found by UOA that we could stick to the non-severe interval. That's on a 97 plymouth with >>150k miles on it.

We have run syn often, but with the quality imporvements of modern oils, even that may not be necessary.

So I personally fundamentally disagree at the characterization of "severe". I think that it is more so an attempt to sell oil changes.
 
I would not call the "3,750 mile OCI for severe duty and 7,500 mile OCI for non-severe duty" a myth. I would call it a best guess rule of thumb the manufactures used that best fits the driving public, before OLM's came out. It would be hard to go too wrong following a 3750-7500 schedule.
 
Originally Posted By: gfh77665
I would not call the "3,750 mile OCI for severe duty and 7,500 mile OCI for non-severe duty" a myth. I would call it a best guess rule of thumb the manufactures used that best fits the driving public, before OLM's came out. It would be hard to go too wrong following a 3750-7500 schedule.


Exactly! Manufacturers' owner's manual recommendations have to cover the user in Bangor, Miami, Dallas, St. Paul, San Diego, and Washington DC, under the best of conditions and the worst. The resulting OCI recommendations have to be conservative.
 
My 2011 Jeep JK Unlimited has an OLM. If I followed its recommendations, I would have three oil changes on it right now. I have changed the oil nine times (in forty months) based on my 5K intervals ( I changed the factory fill at 1K and the Valvoline conventional I replaced it with at 5K). No way I'd feel comfortable following this olm/oci. Might be just fine following the olm, but it's my Jeep, and I think it deserves better.
 
I do a super severe duty OCI at 2000 miles.
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If I was driving all freeway, I might go 3000 miles.
grin.gif
 
With so many variables, they probably lean to a conservative side of things to try avoid overdoing it by a good margin.
With one of my vehicles (Hyundai) with a 10yr/100k warranty, I'm surprised they don't require 3k normal OCI, less for severe duty, and require a stealership perform the OCs to maintain warranty
 
Originally Posted By: Merkava_4
I do a super severe duty OCI at 2000 miles.
laugh.gif


If I was driving all freeway, I might go 3000 miles.
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Ha.
At 10000 mile intervals my engines are spotless inside and after I do change the oil it takes 3000-4000 miles before it's dark enough to see on the dipstick.
You could double that interval since black stone has written on more than one used oil analysis that oil doesn't have an expiry date.
 
Quote:
7,500 mile Oil Myth


Yes, because it's 7500 miles OR 6 months whatever comes first. The 6 month rule takes care of the short trippers. I thought it was common knowledge on BITOG?
 
It sure is a myth if you have one of Toyota's sludge prone engines. My dad met a guy with an Avalon who followed the longest allowable oil change, and his engine was destroyed by sludge. One of the repair staff then told him to ignore the 7500 mile rule unless you have full synthetic, and change every 3000 when using conventional.

Dad stuck with 3000 mile oil changes in his ES300, and never had a lubricant related problem in his engine when he sold the car at ~160,000 miles.

Engine design and vehicle design is a huge factor is how long the oil can last.
 
Not too many users really fall into the severe service catagory, despite what all of the quicky lubes would like you to believe.
The better late model cars have IOLMs to take all of the guesswork out of when the oil needs to be changed.
All others, unless they drive only short trips in a constant winter are probably good to go with drains of at least 5-6K on any oil that complies with the required spec.
A 3750 mile drain interval is absurd for most oils and most uses.
Aside from a few Hyundai owners here, nobody out there in the real world is doing 3750 mile drains.
Many owners are doing unintended extended drains on bulk oil and bottom dollar filters.
They think that an oil change at the quicky lube is some sort of treat for their car.
 
Before OLM, Honda recommends 3,750 miles or 6 months for severe condition and 7,500 mile or 1 year for normal, and this is for conventional oil.

Merkava_4, the oil companies and the filter manufactures are very happy with your schedule oil change. If more drivers change their oil and filter like you, we(oil and filter companies) will make much more profit every quarter.
 
Originally Posted By: HTSS_TR
Merkava_4, the oil companies and the filter manufactures are very happy with your schedule oil change. If more drivers change their oil and filter like you, we(oil and filter companies) will make much more profit every quarter.


Until the oil companies can guaranty me a safe OCI without getting varnish, I have to stick to the extreme cautious side. I can't understand why the oil companies never talk about varnish while they're promoting their oil.
 
my wifes Saturn Outlook OLM just went to 0% at 1950 miles. Last changed in November. Mostly intown short distances in below 0 weather.
 
Originally Posted By: JHZR2
Originally Posted By: ChrisD46
It would appear that everyone living in the suburbs (majority of people) qualify for severe duty usage according to the owners manual !!


because that simply is not the case. Case in point - my mother does five block commutes like six times a day. We found by UOA that we could stick to the non-severe interval. That's on a 97 plymouth with >>150k miles on it.

We have run syn often, but with the quality imporvements of modern oils, even that may not be necessary.

So I personally fundamentally disagree at the characterization of "severe". I think that it is more so an attempt to sell oil changes.


WOW - that is great information. So much for that being "severe"...
smile.gif
 
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