When to Change Oil

[ae1m]

This question arose in the Carlisle C5/C6 Q&A session with Paul. The Owner's Manual disagrees on one point he made. It says on P 6-5 of my 2003 manual to change it once a year regardless of the oil life system computer. Paul stated that Mobil-1 was so good that you only needed to rely on the oil life system.

https://www.mygmlink.com/pdf/go2content/manual/US/en/chevrolet/2003corvette.pdf


Bob

 

[silver98]

Paul has answered this question many times in many different threads on CAC. I believe it was more of an omission rather than a disagreement with the OM.

 

[jrose7004]

I change at 10% on my DIC or one year whichever is sooner!

 

[Z06 Tom]

Confucious Say:

"Oil cheap, engine not..."

 

[atmmac]

ichange it when it tells me to regardless of time.

 

[srs244]

i find it intersting that my 93 convert (bought new in 93) used mobil 1 as mandated by GM, but they required a 3000 mile interval oil change anyway. i could never figure it out and no one at the dealership could ever offer a decent explanation of why a "state of the art" synthetic that was being advertised and touted as the greatest thing in lubrication durability and longevity in 50 years required the same change interval as good old castol gtx or quaker state. it's interesting that the interval is now 1 year. i agree with the statement above, however, oil is loads cheaper than an engine!! i drive in tropical heat, 80 miles round trip, stop and go even on the interstate most of the time. sorry, but i don't believe oil can withstand that type of punishment and hold up properly for any extended period of time. but that's just my opinion. what do i know compared to all the GM engineers??

 

[ae1m]

i find it intersting that my 93 convert (bought new in 93) used mobil 1 as mandated by GM, but they required a 3000 mile interval oil change anyway. i could never figure it out and no one at the dealership could ever offer a decent explanation of why a "state of the art" synthetic that was being advertised and touted as the greatest thing in lubrication durability and longevity in 50 years required the same change interval as good old castol gtx or quaker state. it's interesting that the interval is now 1 year. i agree with the statement above, however, oil is loads cheaper than an engine!! i drive in tropical heat, 80 miles round trip, stop and go even on the interstate most of the time. sorry, but i don't believe oil can withstand that type of punishment and hold up properly for any extended period of time. but that's just my opinion. what do i know compared to all the GM engineers??

Perhaps changing it and the filter has more to do with getting rid of the bits of crap that flake off the radiator and other contaminants than the actual breakdown of the oil.

Bob

 

[srs244]

i would assume "bits of crap" are present in 2002 models as well as 93 models, yet there is a distinct difference in the oil change recommendations per the GM owners manual and recommendations. i still wonder why the difference?? and still will change the oil much more frequently than the currrent factory recommendations.

 

[LLC5]

i would assume "bits of crap" are present in 2002 models as well as 93 models, yet there is a distinct difference in the oil change recommendations per the GM owners manual and recommendations. i still wonder why the difference?? and still will change the oil much more frequently than the currrent factory recommendations.

The reason to change oil frequently is to get rid of the contaminants, not necessarily because the oil has gone bad. Oil is cheaper than engines, even Mobil 1. The difference in 1993 vs. 2002 oil change intervals is G.M. marketing pure and simple. Percieved lower cost of ownership helps sell cars.

 

[srs244]

The reason to change oil frequently is to get rid of the contaminants, not necessarily because the oil has gone bad. Oil is cheaper than engines, even Mobil 1. The difference in 1993 vs. 2002 oil change intervals is G.M. marketing pure and simple. Percieved lower cost of ownership helps sell cars.

exactly my point!!

 

[wwr]

Life of Synthetic

I remember when Mobil 1 and other synthetics hit the street they were saying 25,000 miles between changes. Gradually the interval changed. I know most folks here don't go along with Consumer Reports but they ran oil tests in Taxi Cabs in New York. I don't remember all the numbers but the main conclusion was plain ole oil lasts longer than 3000 miles. They tore down the engines and did that comparision thingy to tell wear on the engine. All my cars get oil change and tire rotation every 5000 miles because the tire folks recommend it. The Corvette I don't know about the tires. They're so wide
and the roads are so bad you have to really have to pay attention to them. I know that the Boxster since it was new had oil changes once a year and most of the cars over there do also. Seems like Camrys etc is 7500 so I guess 5000 will do.

wwr

 

[mrm1149]

imo, the dic will say when it's time........

 

[Patrick]

On the subject of oil changes, I have a question:
Does anyone here modify the viscosity of the oil they use seasonally? That is, do you use a different rating for the summer as opposed to the winter (for those of you who, unlike Remo, are brave enough to drive you Corvette in the winter)? If so, what ratings do you use seasonally?


-Patrick

 

[mrm1149]

I just hang with the 5-30 the manual suggests, suppose I might re-think if I lived somewhere like Arizona..........

 

[DRTH VTR]

the bits of crap that flake off the radiator

I should hope that no radiator contents mix with the oil! Oil and water do not mix.

 

[Z06 Tom]

I run Red Line 10W-30 year round. What my tuner recommends.

imo, the dic will say when it's time........

I stopped listening to mine when I was about 15!

 

[JHL]

i find it intersting that my 93 convert (bought new in 93) used mobil 1 as mandated by GM, but they required a 3000 mile interval oil change anyway. i could never figure it out and no one at the dealership could ever offer a decent explanation of why a "state of the art" synthetic that was being advertised and touted as the greatest thing in lubrication durability and longevity in 50 years required the same change interval as good old castol gtx or quaker state.

Don't suppose it was anything to do with GM and Mobil doing a deal or am I just a synical old bastard these days ?? :L I picked up a brand new Ford recently, first oil change was at 10,000 miles, done just over 20,000 now and it will go into the shop for a service this week as per the recommendation in the handbook. Even the old GTX stuff was good for more than 3,000 miles. To many people with Jiffy Lube shops in the US :L

 

[korvettekarl]

I do change viscosity by the seasons. Of course not everyone lives where it gets to 120 degrees in the summer and down in the 30's-40's in winter. Usually 15-50 in summer and 5-30 in winter. When I rode Harleys (before electric starters) I would have to start trying to start the bike about an hour before I went to work in the winter(only had a shed back then). That straight 60 weight was a #itch to kick over.

 

[Remo]

On the subject of oil changes, I have a question:
Does anyone here modify the viscosity of the oil they use seasonally? That is, do you use a different rating for the summer as opposed to the winter (for those of you who, unlike Remo, are brave enough to drive you Corvette in the winter)? If so, what ratings do you use seasonally?


-Patrick

Well go ahead and make me look like a "scady cat":ugh . But geez, we get around 150 - 200 inches of snow each winter in this area. Those Corvettes don't do well in a 24 inch snow storm. So I'll keep it stored in the winter and drive the 2002 F-150 4X4. BTW the pickup runs 10W30 all year round.

Remo:cool

 

[04cmnthru]

Pretty sure the once a year whether it needs it or not is what you have to do to keep the warranty valid. I think that also applies to GMPP warranties. If thats the case, just do it. Its not that expensive.