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Synthetic Oil

I use Pennzoil 10W30 Full Synthetic oil in all of my vehicles and I change my oil every 5000 miles. Is this a good mileage to this type of oil? My driving conditions are considered normal.

Using full synthetic there’s no reason not to go to the full miles specified by the manufacturer, which I doubt is as low as 5000 miles. What do your manuals say?

My Camry requires the change at 5000, my Optima 7500, my Altima 3000, and my Trailblazer 5000.

If you drive under normal conditions, you’re not getting the benefits from a synthetic oil. Synthetic oils are used under severe conditions where you might see high RPM’s, heavy towing conditions, extreme temperatures, racing, or if the engine is turbo-charged. If you’re not operating under these conditions, you can save a hell of a lot money using a regular oil and changing it at the same interval.


Go here:

Request a free test kit.
Put oil in it once you hit 5k miles, and find out if you need to change it.

This is the only way to truly know.


Thank you! I was thinking the same thing, but the engines seems to run much easier with the Synthetic.

3000 for normal service on your Altima? Is that the Nissan manual, or the dealer? I’m amazed it’s that low! And doesn’t the Trailblazer have an oil life monitor?

Thank you for the sampling information. I will try it.

Normal by whose standards? My ‘normal’ conditions are stop-n-go commuting for 25 miles a day every day of the week in my urban daily driver. This is considered ‘severe’ by most car makers. Also, ‘severe’ includes a bunch of short drives, of a mile or 2 long with constant stops. ‘Normal’ in terms by the car makers is a good 10-15 miles with only 2 or 3 signs or lights to stop for. You know, long stretches of nice, constant speeds.

Using full synthetic, your good for a ‘severe’ duty by changing every 5000 miles. Synthetic motor oil was designed to extend oil change intervals for most fleet owners. It maintains good lubrication properties a lot longer than dino oils.

If you still consider your driving style to be ‘normal’, you can change the interval to 10,000 miles or 6-months to a year. For ‘severe’, you may want to stick to 5000-6000 miles or every 3 to 6 months.

The viscosity of your oil is far more important than whether it is synthetic, which is designed for EXTREME temperatures and engine loadings.

If you live in a cold part of the country you are doing your engine considerable harm by having 10W30 oil; Toyota recommends 5W30 all year round. About 80% of engine wear occurs during cold starts before the oil circulates to the bearings and valve gear. The 10W30 you are using would be OK only for Florida, Hawaii, and Southern California.

If you really want your engine to last, use 5W30, park inside and if the temperature drops below freezing, use an engine block heater for 1.5 hours before starting the engine. You can still use synthetic oil, but, as others point out for normal use it is not cost-effective, except on high-performance turbocharged engines.

The trailblazer does have a life monitor, but I have notice that after 50% of the engines oil life the engine sounds noisier and the oil seems to be very used so I change the oil. The 3000 on the Nissan, if I recall correctly, did come from the manual, but I will verify that again.

My vehicles are located in central texas. I have then garaged, but I think after all of these coommits I will go back to using conventional 5W30 or extend the mileage of the synthetic. The later concerns me.

Unless you abuse your vehicle, you can easily go 7.5k or even 10k with synthetic. Ive been doing it for 40 years.

If car is under warranty…do NOT go beyond the car manufacturers oil change recommendations or it may void our warranty.

Personally I don’t car what oil you use…I’d never go beyond 5k unless you have an oil analysis done. 5k should be fine.

5000-7500 is my comfort zone and I am liking of the benefits of saving by using the conventional oil. I will return to conventional oil and do the mileage oil change listed in this response. It looks like from all of the comments we all have basically the same thoughts. I have been using Pennzoil for years and change my oil at 5000 miles. I have had mileage on vehicles at 200,000 whith no noticeable oil usage from the dipstick check. I appreciate all of the advice. If there are any suggestions on what type of oil to use please send me a note. I always welcome new knowledge. Robert

Doesn’t the Pennz bottle tell you? The realsynthetic oils such Mobil 1 and Redline tell you. Maybe you should switch to true synthetics.

3000 for normal service on your Altima? Is that the Nissan manual, or the dealer?

??? That sounds like ADP to me.


Why would you pay $22.50 to have your oil analyzed when you could simply have your oil changed for that same amount… less if you do it yourself.?

I want to read those so I will go to wal-mart and see just how many miles they recommend. The Pennzoil bottle does’nt give a mileage. I will send you my response after I do my research.

This is the standard I would like, but I will do a sample check and send you a note.