Oil recommendation

[geicogecko]

1. 98 Grand Prix GT, non-supercharged.

2. Recommended is 10w30 above 0F. The car has an oil life monitor, but I don't use it. Recommended OCI is 3000-7500mi.

3. Central and south FL. The coldest I have ever seen it get here is 30, and that wasn't for very long.

4. I tend to drive fairly fast, usually 5mph over, hard acceleration, hard braking, fast turns. I'm an agressive driver.

5. 3-6 days/wk, my commute is 12 miles total.
3-6 weekend days a month, I drive 100 miles round trip.
A few times per year, I drive from Central to South FL, which is 320 miles each way. That is all highway driving.

6. My lower intake manifold gasket is leaking, so I tend to run hot.

7. I am currently using Castrol 10w30 HM. I prefer Castrol, but if another brand will work better, let me know. I tend to change oil every 3k mi., and change the filter every other time. I currently have a FRAM in, but after reading this site, I am switching to Purolator.

I don't mind the current 3k schedule. I'd rather not go synthetic because of the extra cost, and I think my engine is pretty durable.

Any other info needed, just ask.

 

[sicko]

Assuming you want to stick with a High Mileage oil, I'd personally go with either Valvoline MaxLife, or Pennzoil High Mileage, either one in a 5w30. I believe both are a semi-synthetic (if I recall Pennzoil will tell you it's a semi-syn if you contact them, but they don't advertise it as such....but you really need to double check that). MaxLife has shown some great wear numbers in used oil analysis and for the price it's hard to beat. Pennzoil is a quality oil, and again you have to contact them regarding it being a semi-syn, but if it is they try to get a higher % of synthetic in their semi-syns then a lot of other manufacturer's are suspected of using. But again, you need to contact them.

My suggestions of Valvoline and Pennzoil should in no way be viewed as insulting Castrol, it's a fine oil, it's just it tends to be pricer than the other two and I've never seen anything to indicate it's worth the extra couple of bucks.

I would also extend the oil change interval (OCI) beyond 3k miles. Your vehicle has an oil life monitor, and they have shown to be very accurate. However, if you're concerned then simply push your OCI beyond 3k to maybe 4.5k. It'll slightly reduce the number of oil changes you need to do, it should still be well within what your oil life monitor says the oil can go, and it should in no way have a negative affect on your vehicle.

 

[geicogecko]

I usually get the Castrol on sale. I'm not sure if the HM actually does anything, but like I said, it's on sale, so it's maybe a dollar more. Do you think the Castrol will peform the same as Valv or Penn?

And how come 5W? The ambients down here?

And I forgot a big piece of info: mileage! I'm coming up on 125k.

I didn't realize OLMs were that accurate. I was always taught to change every 3k. But if it'll save me money, I'll listen to the car.

 

[J. A. Rizzo]

Now you mentioned the mileage and sicko mentioned the OLM, I think you're on track pretty well. The HM Valvoline and Pennzoil sicko mentioned are good. If it might be running hot, you might also consider Motorcraft semi-syn in 10w30. That's an inexpensive bit of insurance over conventional for the additional heat, has shown in many used oil analysis to be an excellent product, and if you follow the OLM (heartily recommended) instead of 3k changes, your costs will probably be the same or less and you'll spend less time dealing with less used oil. Good call on the Purolator. Wix and most anything else is better than what you're doing now.

Do you plan to fix the LIM gasket issue?

 

[Old Mustang Guy]

I think what your doing now is good, especially until you get the manifold gasket replaced.

 

[geicogecko]

I will. I'm a bit tight on money, and it's been leaking for years. It's recently gotten worse, as in the past year, but it doesn't run too hot. As long as I keep it moving, it's fine.

My next change will probably be Pennzoil High Mileage 5w, but I'll have to check some prices.

 

[FZ1]

Run a full synthetic. Synthetics run a little cooler. Hope this helps.

 

[J. A. Rizzo]

Originally Posted By: FZ1
Run a full synthetic. Synthetics run a little cooler. Hope this helps.


??? Really?

 

[Bill in Utah]

Coolant leak? Short of $$?

This is what I'd suggest.

1. TAKE IT EASY with the vehicle. DRIVE it softly.

2. FREQUENT oil changes till you FIX the leak.

3. SAVE your $$ and GET the LEAK fixed ASAP. Run ANY xW-30 oil that is the cheapest.

With coolant issues and the engine running hot no oil is going to help you. Your NUMBER one goal should be FIXING the LIM issue and then once you've taken care of that, oil choice can be a concern.

Coolant in the engine is a major problem and NO oil is going to reduce its effects on the bearings and other parts. Changing the oil OFTEN will help SLIGHTLY.

Take care, Bill

PS:

 

[shpankey]

Stick with the 10w30. Advance Auto Parts has a special for 5 quarts of Pennzoil High Mileage or Quaker State High Mileage with a Pure 1 filter for $20. Change often and fix it ASAP or your not going to have a car at all. You need to think of the damage and wear on your engine driving it like this. Time to call in favors or help from family and friends. Good luck bud.

 

[Nyquist]

My folks have a vehicle with the same engine transmission combo. In Iowa they've run 10w30 in the warm season and 5w30 in the cool season when average ambient high temperatures fall below 50 degrees. The oil used was Formula Shell.

The car now has 225,000 miles on it, so I'm assuming they've done something right.

 

[geicogecko]

Alright well ignoring the manifold issue, what would the recommendation be? 10W or 5W?

 

[shpankey]

Quote:
2. Recommended is 10w30 above 0F. The car has an oil life monitor, but I don't use it. Recommended OCI is 3000-7500mi.

3. Central and south FL. The coldest I have ever seen it get here is 30, and that wasn't for very long.


I would say, based on those two things, 10w30