How many of you go 7500 miles on conventional oil?

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Aug 30, 2004
I do. I change my conventional oil annually or 7500 miles, whichever comes first. And I'm rarely on time either, so it's usually closer to 9k.

Anyway, what I do is irrelevant. My question is-- why are so many of you hesitant to run your conventional oil for longer intervals? I constantly read about BITOGers change their conventional oil at 5k. Some even at 3k. It makes me cringe to read how wasteful some of you are.

Conventional oils have improved significantly over the last few decades, especially over these last few years. OEMs have been specifying 7500 mile intervals for normal service for well over a decade now.

Now, unless you drive a vehicle that is a notorious sludger, or your driving style involves "grandma duty," if your OEM allows for a 7500 mile interval on conventional oil under normal service, what's your excuse for not following it?
normal OCI for my car is 15,000 km

i follow the severe schedule at 7,500km because of trips less than 3km 4 times a day. in pretty warm temps though. if i read the book critically i could go 15,000km just fine with my driving conditions, as they mention "short trips IN FREEZING WEATHER" as severe duty.

i use synth blend or conventional.

If i had normal duty i'd use M1 for 15,000km.
For every person that changes their oil at 5k miles, there's 2 people who don't change it till 15k. It all averages out in the end.
I usually go about 5k in the winter months, change it in the spring, then again in the fall.

Usually get about 6k out of the spring/summer run.

I'm using 10 dollar quaker state motor oil (for five quarts).

Twice a year is just fine for me.
I go that far on dino in the summer if all the miles are highway....low stress miles...I will change at half that mileage in winter or with more city miles.....
Sorta-kinda. I do a 4+1 blend of Castrol GTX and Syntec (a Grp III) in our Honda. Is Group III "conventional?" Some here would say so. For me 7500 miles works out to about 18 months.
My uncle goes 7500 on Penz YB in his Chrysler Concorde. Did it in his previous Concorde and the Skylark before that. All short-trip driving. It makes me cringe.
My owner's manual for the Impreza says 7,500 miles OCI. The Dakota says 6,000. The Chevy Venture has an OCM which clicks on at around 7,000 miles also. Modern 5w20 5w30 is group 2+ or group 2, really well "engineered".
I don't think it's a good idea to run conv. that long. If you only plan to keep you vehicle 2-3 years, OK, but for the long haul synt. is better for the 7-10,000 OCIs.
I have Toyotas all in warranty....5000 OCI on synthetic. My neighbor has a Lexus RX300 V6 he has been going 7500 on dino for it is starting to smoke....I told him about the engine sludge recall on that model and why he should take it in. He got the paperwork from Toyota but let it lapse. I figure it should be about 6 months before I hear the swearing coming from his garage when it seizes.
I do. I'd 'like' to change my oil closer to 5-6k, but time, money, etc...and I'm always closer to 8-9k on changes.

Hasn't seemed to have done the car any harm, oil still looks 'decent' when drained, not all chunky, black or really nasty.

Funny you posted this, for me. I'm at about 7900 miles on a fill of dino, and planing on changin it later this week!
Working in a dealer on vehicles that specify 7500 mile service intervals but only recommend synthetic (we pump semi-syn Castrol), I wouldn't go that long on semi-syn that we use.

Of course, our engines are turbocharged and that is pretty hard on oil.

Personally, I change every 7500 miles using a full syn, but I do nothing buy highway. I can probably go longer, but I don't see the need to push it.
5K on Dino. That's a good safe number. Could you push it more, sure, but why would you?
Originally Posted By: wcbcruzer
For every person that changes their oil at 5k miles, there's 2 people who don't change it till 15k. It all averages out in the end.
So my buddy's friend who changes every 400-700 miles is okay as it only brings the average down a little bit.
I change at 5k miles with dino. My car specs 5k severe, 10k normal service. My driving habits are variable, so I technically fit in the severe category. Havent gotten around to UOA to optimize interval becuase one OCI driving habit is diferent from the next.
I go by the GM OLM in my '06 Buick with the Northstar V8 and a massive 7.5 qrt sump. The OLM takes me out to about 11k miles. I alternate between SuperTech 5w30 and Kendall GT-1 without a hitch.
Depends on my car.

7500 on my IS250 but 5000 on my older cars, because IS has 6.6qt sump for a 2.5L and the older cars have 3 qt sump for 1.6L and 4 qt sump for a 1.8L. The IS also runs 95% highway commute for 1 hour each way.
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