Home Forums Hunting & Shooting Hunter's Campfire Your experiences: synthetic motor oil and change periods

Old gearhead here, but very little experience with synthetic motor oil. It was in our MoHome engine when I bought it and have continued with it for an oil and filter change. It is a 2002 Chev 8.1 Vortec/FI setup with 75K miles on the odometer, and almost all running is at 65 to 70 mph on highways. No dirt roads, and mostly clean air. It consumes about 1 qt. of the oil in about 2500 to 3000 miles.

The current oil is at 6k miles, is still a shade of amber and has no fuel smell. It feels quite smooth. My idea is to install a new oil filter and run this oil up to 10k or 11k miles. What do you think? (The synth oil is Costco's finest Kirkland)

I have a hard time finding conventional motor oil these days - you seeing that in your area CCCC ?

I only use full syntyhetic Mobil 1 and have for the past 41 years. I do 6,000 mile oil and filter changes that correspond with my 6,000 mile tire rotations. In the 20 or so trucks, cars, and SUVs that we've had over that time only one engine wasn't still running strong and clean at 200,000, a 1987 GM 2.8L V6 that had very significant ring wear that caused flecks of carbon around 3 to 5mm to build up in the oil. That engine was in an S10 Blazer that had a 4.11 rear end and the low gearing resulted in higher average RPMs, more heat, and more wear. It was a go nearly anywhere SUV, but if you wanted to go anywhere fast, you had to put your foot into it.

I firmly believe that using good oil, a good filter, and changing your oil at regular interval is cheap protection for any engine. I have seen the inside of an engine case that was full of sludge because the owner only added oil, never change the oil or the filter. I change the oil in my other engines, both large and small, annually even if they don't get a lot of use. The engine on my 48kW GENERAC auxillary power unit has a 5.4L V8 and runs for about 30 minutes months or 6 hours per year, not much, but changing the oil and filter doesn't cost much and it gives me peace of mind.

So far, it has not been scarce, but is much more pricey. We have a bunch of 50 year old old Chevy trucks and Corvette, so I gathered up a respectable supply of conventional oil when we lived up in the high remote country - and moved it here. I run conventional Delo in the 2001 Cummins - still available at Costco.

I do need experienced insights on running the synthetic 10k miles with a 5k or so filter change.

I'm not much of a mechanic. My dad taught me that oil is the "lifeblood" of any engine. I change (or have changed) all my oil at half the recommended intervals. This includes the vehicles with synthetic and my outboards.

I have NEVER had an oil related problem with any motor, other than a push mower.

I'm not wealthy, but oil changes are a hell of a lot cheaper than mechanics.

Full synthetic, 10k intervals, change filter every time. Used oil analysis, which is the ONLY way to prove your oil is performing up to spec, is done at every oil change. Cheap insurance.

I started using it in a couple of vehicles after using conventional for years. Usually if I did the changing I'd use Valvoline racing oil on the recommendation of a mechanic. Now it's Mobil 1 or similar.

Vehicle 1: 01 Tacoma, 4 cyl, 4wd. Used a bunch for towing and carrying a decent load for that truck between E WA as far as Fresno CA for a couple of seasons back and forth. As in 500+/- lbs in the bed and cab, and towing a cargo trailer with that much again. Now it's used for hunting trips and going to the feed store and such. Purchased with 110K miles, started using the Mobil 1 on the first oil change after purchase. Originally kept with the old 3-4K mile rule, then talked to others and started going to 5K miles. Then found out about oil analysis, +/- $15 kit from the local Caterpillar dealer. I've installed Fumoto valves in any car I change oil on so it makes sampling really easy. Good filters, Bosch extra mileage type when I can find them. I'm now at 7500 miles between changes and probably going to 10K based on analysis. Truck now has 250k+ miles on it.

Vehicle 2: 2004 Toyota Matrix, 4Cyl now our daily driver. Probably started with the synthetic oil at about 125K, now has 225K miles on it. Same/same with this one, analysis showed "normal" on all parameters last test, so I'll likely go to 10K on this change. Now at about 8K. Gets about 4K before needing 1/2 quart or so.

I also have used a shot of Marvel Mystery Oil with every change, probably going back to the 70s on about every vehicle I've owned. Don't know if it's helped, but apparently with the results I'm getting it hasn't hurt anything either.

C's, if your worried, get a test kit from Caterpillar or some other outfit that will analyze your oil. Another recommendation from a mechanic. If it's good enough for over the road trucking companies, ship owners, and race car outfits, it's good enough for me.

I have switched to the extended life syn oil and filters and run mine for 10,000.

I have an old 2002 Ford Ranger with 219,000 miles which is currently running at 24,000 miles since the last oil change. Pennzoil Platinum High Mileage.

I don't care if it does, but the damn thing just won't die.

I run synthetic to 10,000+. Mobile 1. Last two trucks I sold with 289,000 and 303,000 miles running strong. Currently running Mobile 1 in a 135,000 mile Dodge pu.

I have the dealer change mine every 5000 miles. Believe he uses a blend. Have never had an oil related engine issue. As others have said, cheap insurance to keep it at the right level and performing as oil should.

I use full synthetic oil in my cars. I change the oil and filter in my cars every 10,000 miles. I feel no need to do it any more often than that. They are both 2019 models; engines nowadays are so much better machined than they were when I was younger, and oil is much better now than it was then; and full synthetic takes it to another level. When I bought my 2013 Outback new (it used full synthetic oil as well), I only changed the oil and filter every 10,000 miles in it as well. I traded it in at 150,000 miles; never, ever had a maintenance issue. And I routinely took it on schit that was more like a burro trail instead of a road. Rough-ass country. Ran like a top the entire time I had it.

With even a synthetic change costing little more than a tank of gas these days, there are a lot better things to save money on.

If I “ran” syn oil, that’s exactly what I’d do.

Synthetic oil is at its best @ high mileage intervals and cold temps.

It’s what I put in my daughters car when she lived in Fairbanks and when she and a friend took a cross country trip after college ( collage, for the ‘fire illiterati).

She put ~15K on that trip with a filter change and top off halfway.

For my uses, I mostly “run” cheaper Dino oil and change ~5K because of cooler temps (especially) winter and short trips, thusly not getting to full op temp and to remove condensation.

I bet you’re one of us that’s not got gobs of money, but you’re very wealthy.
😉😉

I have a Chevy truck with A 4.3 V6. I changed the oil at 1K to Mobile1 and I still have it with 187K miles. I change the oil once a year which is about 12K, until I retired. Still going strong, but the body is showing age.

Bought a KIA for my better half in '17, changed the oil three times using Mobile1 and their oil filter/

My Dodge '05 Cummins gets RotellaT 15/40, but I have to do hose changes that will require pulling the oil filter, so for the first time being retired, I have Costco 15/40 oil. Haven't done it yet, but I figure it will still out last me!

10,000 Mobil one and filter changes for me in a Ford 460 in a motor home.
Your plan to change the filter at 6 and everything at 10 or 11,000 sounds like a good one.

I just counted 16 various diesel engines on the farm.
(Jim probably has +20...lol)

Of those, six run on 5w-40 Rotella T6(year-round).

Three F350's and three JD loader tractors.


Cold weather and extended run times are a selling point.

I know they start easier, no idea on engine wear benefits.


Figure roughly 200-300 hours in between changes.





15w-40 Rotella in everything else.

I am very rich!

Just broke.

....................Many varying opinions and experiences on here. Depends I guess on which synthetic oil you plan to use as they vary in quality.........After all of the free oil changes from the dealer expired on my bought new 2015 Ram 1500 Hemi at 36K miles, I converted over to 5w/20 Amsoil Signature Series which is their best. This particular oil is rated at 1 year or 25K miles whichever comes first. I change this oil and change the oil filter every 15K miles using an extended life oil filter. My Hemi uses about 1 quart every 8K miles. Now has nearly 140K miles on it and it still runs like when I drove it off of the showroom floor brand new.....Before converting over and after doing a lot of research comparing oil breakdown tests after x thousands of miles with other 100% synthetic oils, Amsoil is perhaps one of the best synthetic oils, if not the best synthetic oil on the planet.....Yep! It's more expensive, but imo worth it.