Thanks gentlemen! Do you think the Castrol GTX which is a semi-syn now will flow as fast on start up as Mobil 1 high mileage in the winter? I'm concerned about that since the truck sits for long periods of time. I guess the film strength and how it clings onto the engine parts while sitting for so long might be a thing to consider? Does anyone know how this might work between GTX and M1HM?
27 year old GMC Sierra 93,000 miles. Should I switch to full synthetic(Mobil 1)?
- Thread starter Chris B.
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No, I never had the oil professionally examined.
M1 xw40 would be my first choice if changing over to that brand. Otherwise you may notice oil consumption with a lighter weight and changing over to M1. Another option would be one of the Castrol synthetics. One more would be Quaker State euro 5w40.
M1 5w40 Turbo Diesel Truck is another excellent choice. Comes in a gallon container and right now about $28. At Walmart and even AAP for that price.
M1 5w40 Turbo Diesel Truck is another excellent choice. Comes in a gallon container and right now about $28. At Walmart and even AAP for that price.
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Wow! What a nice truck. I'm definitely with the just keep doing as you have been doing camp. Changing not highly likely to do harm but it could and not likely to gain anything so why ?
My 03 Chevy S10 with around 130,000 miles is doing just fine, I originally was running QS All Mileage which is a synthetic blend but I wanted to switch to a full synthetic high mileage and QS Full Synthetic High Mileage wasn't available at the time due to some shortage so I went with the Mobil 1 High Mileage Triple Action Formula and it's going good so far.
I would go with a High Mileage option though.
I would go with a High Mileage option though.
Dated a girl back in the middle 90s whos Dad bought that same exact truck brand new in 1996 -- but in white and minus the cab. Little Deja vu there initially. Your truck looks great till this day and congrats. Cant see Mobil One HM 5W30 or Mobil One 0W40 being a bad decision at all. Flip a coin....
Really, when you get down to it, most ANY high mileage, full synthetic oil is going to work to your benefit. The fact is that the seals and gaskets on a 27 year old vehicle are going to show signs of hardening and stiffening, from thousands of heating and cooling cycles over the last quarter century plus of operation.
Leaks are going to happen. Much like grey hair on a Social Security recipient. It's the nature of the beast. By using a high mileage, full synthetic oil, it will have a good additive package to help prevent this. And the more you can put off having leaks and such, the better.
I've even read where some guys use high mileage oil right off the bat in a new vehicle. This to help keep seals soft. Supposedly high mileage oils also have good additive packages in them, that make them more desirable. Regardless, at this stage in the game, your truck is taylor made for it.
Leaks are going to happen. Much like grey hair on a Social Security recipient. It's the nature of the beast. By using a high mileage, full synthetic oil, it will have a good additive package to help prevent this. And the more you can put off having leaks and such, the better.
I've even read where some guys use high mileage oil right off the bat in a new vehicle. This to help keep seals soft. Supposedly high mileage oils also have good additive packages in them, that make them more desirable. Regardless, at this stage in the game, your truck is taylor made for it.
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I would start running a HM semi-synthetic if that were my truck, like GTX HM or Pennzoil HM.
I've experienced old vehicles leaking immediately upon making the switch to Mobil 1 (even HM).
I've experienced old vehicles leaking immediately upon making the switch to Mobil 1 (even HM).
I'll try to answer if I may!
I believe that if you look(on the shelves) at oils that are labeled synthetic blend that, you'll pay more for them specifically. All conventional oils today that come in 5W20/5W30/10W30 and maybe even 10W40 are now synthetic blends whether they say it or not. Although the conventional(syn/blend) oils may only be somewhere between 5%-15% synthetic depending on how much synthetic the blender had to use(grade dependent) to meet the stringent standard of todays oils. And I heard years ago here at BITOG(can't find the thread) that 7% synthetic was the minimum to be considered a blend by the API. However, I can't find anything to substantiate that.
I'm not saying that blends are bad however, synthetic blend oils in my opinion and just my opinion, have been more about marketing and less about being substantially better, as [MOST] are not even close to a 50/50 mix. I'm not saying that there isn't any 50/50 blend out there...but where? I have used plenty of blend oils especially when I got them at a really low price.
Maybe(and again, IMO) 20% synthetic/80% conventional. Or 25/75 but not 50/50. You can make your own blend with as much or as little synthetic oil as you wish or have on hand. YES, oils can be mixed!
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Just my personal preference. I thought you said you don't drive in the Winter? What's the obsession over cold flow?
Sorry, my comment was related to the full syn version of Castrol GTX. I am talking about watching the shelf, because there is so much full synthetic these days, and less choice in blends or conventional oils.
Nice truck. Since you've had good results with Castrol, why not switch to a Castrol high mileage synthetic blend?
10W30 Duron works fine in my 1973 GMC crew cab. There are no specific “high mileage” HDEOs. Why? Because they are all suitable for high mileage applications.
Sometime I still have to start it up in below zero temps after sitting for a long time.
I keep thinking about this and I just may!
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