oil opinions

[Ruby Fan]

Your opinions please: I have 5-30W Mobil 1 in my '85. By the time May rolls around, I don't think I will have 800 miles on the oil. Would you people change over to 10-30W, (syn or dino) for the summer or just leave it until my regular change interval? I change oil every 2K. The '85 era models have aux oil coolers and the engine never seems to get that hot, so it would be kind of sinful to keep dumping out syn oil before its time. So whadda say?

 

[c4cruiser]

I use Mobil-1 5W-30 in both my 87 L98 and 92 LT1. Neither car gets more than 3K per year and the 87 sees a lot of autocross and track days. I usually only change oil and filter once a year in the 92 (springtime) and it usually sits during the winter. I do try to take it out once a month for a 20-30 minute drive to get any condensation or moisture out of the engine.

Because the 87 sees more severe duty, I'll typically start by changing oil in the spring and after every other track day. The motor in the car is new with only 6K miles on it.

I buy Mobil-1 at either Wally World or the local Costco. Either place has it for $4/qt although W-W has the large 5-quart jugs at $19.72 which is handier for doing a oil change. Costco carries boxes of 6 1-qt bottles for $24.

2K between oil changes is OK if that's what you want to do but IMHO, not really necessary. 3K is the most common service interval be it dino or synthetics. I don't believe in the 7K or 10K intervals that the factory recommends in some new cars.

One big key to long oil life (and engine life!!) is a quality oil filter. I quit using Fram after reading the oil filter studies that shows them to be junk with inferior filtering media and even less material than others. K&N, Mobil-1, or Purolator are excellent filters as is the NAPA Gold.

 

[lbitp37]

In my opinion change at 3000 miles.

 

[tnovot]

I have always heard that oil can oxidize when exposed to air - even if just sitting in the bottom of the oil pan. True, synthetic should be more resistant.
Just MHO; I change mine based on time rather than mileage because it doesn't always get driven that much. I'd say 12 months (or maybe less if it has been driven on numerous short trips) should be the interval. Like you, I only put 500-800 miles per year and use a good grade of dino like Quaker State rather than synthetic.
If you don't want to dump the low mileage oil, save it for your mower or use it for bar oil for the chainsaw or give it to someone who has an oil burner (car or winter heater) or ???
Adding to what C4 said about filters, the AC filters were also very highly rated in the oil filter study.
Terry

 

[Vettefan87]

If I were you I would change it before you start driving it again, and I would not go anything less then 10w30, 5w30 is like pee water, I was putting it into my Escort and couldn't believe how thin it actually is.

 

[PLRX]

I use Royal Purple, I change synthec oil every 5K

 

[Hib Halverson]

No Corvette which is driven aggressively should use the factory-fill 5W30 which is recommended by GM mainly to improve fuel economy. In fact, all Corvettes for which 5W30 is recommended may use 10W30 when 5W30 is not available and some older model years actually recommend 10W30 in hot weather.

The problem with 5w30 is that it has more VI improvers in it than 10W30 and, for that reason, tends to get pretty thin at high oil temps, say 230 deg and above.

If you want maximum durability from your engine and highest performance over a longer life, use a 10W30. A synthesized hydrocarbon based product such as Mobil 1 is good and an ester-based oil, such as Red Line, is better.

There is no reason to observe an oil drain interval shorter than the factory recomendation or the what the oil life moniter (if applicable) indicates unless 1) the car is driven so little that you need to change it annually rather than by mileage or 2) the car is operated in a dusty environment.

I use Red Line 10W30 in all my cars with cats and use Red Line SAE30 Race Oil in cars without cats. The ones which are driven more than 10000 miles in 2 years are changed every 18,0000 miles. The cars which are not, are changed every two years. Regardless of oil drain interval, I change filters on V8s and V6s with small filters every 3000 miles and on V8s with large filters every 5000 miles.

I've used this drain interval for about a decade and it's backed up by about 10 yrs. worth of spectrographic oil analysis data.

 

[safety_match]

Something else to think about...whatever interval you decide to change your oil with I would make the oil change just before you tuck it away for the winter. It is better to have it sit with clean oil in it than contaminated oil.

Safety

 

[PLRX]

I agree:Silly

 

[MyOtherCar]

Your opinions please: I have 5-30W Mobil 1 in my '85. By the time May rolls around, I don't think I will have 800 miles on the oil. Would you people change over to 10-30W, (syn or dino) for the summer or just leave it until my regular change interval? I change oil every 2K. The '85 era models have aux oil coolers and the engine never seems to get that hot, so it would be kind of sinful to keep dumping out syn oil before its time. So whadda say?

Ahhh, the "ideal" oil change.... everyone has their own way of doing it which is probably ingrained in us from all the previous years of changing oil. I don't know of anyone who feels comfortable changing oil at the Mfg's recommended interval, or waiting for the idiot light on the dash to illuminate, telling you an oil change is due.

Actually, I once (or twice) heard that it is not a matter of the oil wearing out, rather it is the oil filter trapping all the particulates that it can handle and itself should be changed. That said, I certainly don't believe you need to change the oil every 2K, especially because you're using synthetic. Normal driving conditions???, every 5K should suffice, probably even longer. Winter storage shouldn't bother it as long as you run it periodically. If it's in cold storage than I would change the oil annually.

Someone made comment about the Fram oil filters. If reading this, would you post a link to the reference for that data? Thanks, I ask because I've been using Fram oil filters for the past 25+ years and never had any problems in any of my vehicles. In the case of the Corvette, I find Fram filters few and far between, apparently there is some marketing change going on. So I use NAPA in its place.

On my vehicles without synthetic I change the oil every 4K. That works well because every other change I rotate the tires. Just easier to keep track. Good luck and I hope you come across an interval that you feel comfortable with.

 

[Evolution1980]

Someone made comment about the Fram oil filters. If reading this, would you post a link to the reference for that data?

http://minimopar.knizefamily.net/oilfilterstudy.html

The above link is pretty much the same 'study' that everyone else goes by. I don't believe that this is the "original" study, but many people have taken the webpages and hosted them themselves. I believe that the original author stopped doing the comparisons. I know for a fact that the link above is NOT the one that I originally saw a year or two back. Same study, different web host.

 

[WhalePirot]

(Chuckling at the everyone's oil change opinion comment.) Man, did we ever beat this one a while back.

My diffy professional claims that non-synthetics lube better and after losing a main bearing after years of Mobil One, I switched to a quality, non-synthetic oil (Valvoline). I have a lot of cars and have used 5k for an oil and filter changes. I also do brake inspections and more while rotating the tires. My cars get warmed up enough so I don't worry about the nasties forming from condensation. I feel 5k is conservative and is VERY easy to remember without referring to each car's log.

Perhaps Hib's comment about the thin oils and hard driving speaks to my feeling that there is more to oil than how slippery it is. Certainly high temperature characteristics are a consideration, and a form of insurance against overheat disasters, but thicker oil is also acts as a cushion in the micro-spaces it fills. The syns do better at much higher temperatures, but I opt for the 'cushion'.

While not an apples/apples comparison, the Vette went 105k on Mobile One before spinning a main; the old 735iL keeps on chugging, quite nicely, at 223k+ on normal dino lube.

Regardless, we each have varied driving patterns and conditionswhich dictate difering intervals. More frequent changes are quite cheap insurance and the recycling can take many forms.