What is the best synthetic oil for a 2500hd Chevrolet Silverado 4x4

Matter of opinion. Ask 10 people you will get 10 different answers, I prefer and have had great performance with Mobil1. For a 2001, (high mileage?) 5W30 or 10W40. And the filter is just as important. Get a quality filter

Thank you... and you are right about 10 different answers.

I use Amsoil 10w40 with a Wix oil filter, it is rated high but not as the best but definitely very good, was surprised to see the Fram extra guard & high mileage filters rated up-there on a comparison chart I was looking at.

Engine size? Run what the manufacturer recommends. I'd recommend A/C Delco filters and Mobil1 oil in the recommended weight (probably 3w30).

A/C Delco are one of the worst filters for filtration. Sorry, But the Mobil-1 oil is good oil.

A/C Delco designed by GM for GM. I personally would use Motorcraft if available or Wix, but I always recommend manufacturer filters.

All it is, is a gimmick. There are actual studies out there of testing oil filter brands. I use Wix, it is rated pretty good, If I remember right Bosh oil filters were at the top.

My first question if we were standing together would be, Why are you asking? Are you using regular oil in there now? Look at the studies on changing to synthetic oil on high mileage engines after running them on regular oil. What I have read, and have been told, the synthetic oil will really clean out your engine. It will remove the protective barrier built up on old gaskets and then you will have a lot of leaks. This is a consideration. The old junk stored will be carried away in the oil throughout your engine until it fills your filter. If you do a complete rebuild of the engine, then you can start using the synthetic oil. If you feel switching will save the engine, too late my friend. Good filters keep contaminates out of the oil that causes engine wear. Look at engines that use natural gas. No contaminates in the fuel like regular gas, and the engines can go well over 200,000 miles and very little wear is shown because of clean fuel, and no fossil fuel contaminates. When the oil is changed, it is not black, but nearly the same color as when put in. So if trying to prolong the life of the engine by changing the type of oil you put in, forget doing it. I just bought a new GMC SUV and GM puts in a mixture of regular and synthetic oil blend. They do not recommend using straight synthetic oil. Why? Don't know unless it is their own oil and will make more money selling their oil. If I change out to another type it voids the GM warranty I was informed.

califcarson, probably GM wants any oil you use to be Dexos certified. If the service department told you no synthetic then I would think they are wrong and I would refer to my owner's manual for guidance. I would be curious as to which GM SUV you have. A new direct injection engine will get synthetic at my house. My new to me Lincoln MKZ 3.7 is not direct injection and non-turbo so it gets Motorcraft synthetic blend and a Motorcraft filter installed by me.

Continued...my 2013 F150 is a twin turbo 3.5 Ecoboost with direct injection and it gets only synthetic. Regular non synthetic oil in most vehicles is adequate, but needs to be changed on a more frequent basis.

I have a new GMC Terrain 4 banger. I think it is direct injection I was told what GM wants is the oil that is a mix of both blends. Who know if any of the engineers talk to each other. There are different blends of oil for different purposes I know, same as different weights for different reasons. When I buy a new vehicle and am told use this or else, as long as they are paying for the oil changes, they can put in Wesson oil for all I care. Does the heat of the engine have anything to do with regular vs. synthetic oil break down? To me this sounds like the best of both worlds, or the worst of both worlds. I didn't know they could mix. Yes synthetic oil lasts longer. I also was told the oil sensor tells the computer the length of life left on the oil. I was told this when I asked about the sensor being reset at 3,000 miles when synthetic oil normally is 6,000 miles or around there. The computer read by the sensor determines when the gauges tells the information system when to change oil. Now that can be a bit un- nerving.

califcarson, I'm with you, if GM is paying for the maintenance they can use what they want as far as oil goes. The oil life monitor is more than just a sensor it is an algorithm within the computer programming that monitors all kinds of parameters to determine when the oil needs to be changed. I understand that these algorithms (programs) are fairly sophisticated and do a pretty good job at monitoring what is going on in the engine.

Things sure have changed since the 50s, that's for sure.

Honestly .. the best thing to determine what filter you want to use is get a few and rip them apart to see what the insides look like to see the actual quality and filter element.. As for the oil ... The blend is good if the vehic requires only conventional , if it requires synthetic then thats what it is and should be .... If your vehicle requires conventional or the blend and you want to go to full synthetic have at it .. but after 50k miles and dont look back or think about going back to conventional

I use Hastings filters only best one made.

I have used Mobil 1 oil in ALL MY GAS-engined vehicles for about thirty (30) years & I have never had an engine problem of any kind. I live in Canada where winter starts are VERY HARD on engines but NEVER with the full synthetic Mobil 1 5/30. I have oil pressure gauges in all my vehicles which tell the whole story .... INSTANT OIL PRESSURE, no matter if -40 (truly) outside. I often go to the hot temps of Southern USA pulling a 5th wheel travel trailer in 85 to 90F temps .... still have good oil pressure (doesn’t thin out like water) & maintains its viscosity even when very HOT. Don’t be alarmed by the fact that Mobil 1 seems extremely THIN .... that’s its beauty .... compared to regular oils, Mobil 1 has much wider viscosity attributes so much wider “pour points”. I vary how often I change my Mobil 1 dependant on if summer or winter & how many miles I’m driving monthly. Dirty oil is still “dirty oil” and contaminants from acid/carbon buildup in crankcase or dirt are harmful to today’s close fitting internals. In ideal weather conditions & higher miles/month, I may go as many as 7K miles. In winter & minimal miles/month, as low as 3K miles. Oil (even Mobil 1) expense beats engine breakdown, my downtime, tow jobs & my frustration every time. Bryan, Calgary, Alberta, Canada

JON Myth #3: Synthetic engine oils can wear down seals in an engine and cause leaks. This is an often-cited myth. In fact, if your seals and gaskets are in good condition, synthetic oil will not leak in your engine. Synthetic oil has not been shown to deteriorate engine seals or gaskets. But it might find an existing leak. The smaller molecules of synthetic oil are able to pass through very small cracks and crevices that the larger molecules of petroleum-based oil cannot. Eventually, those small cracks and crevices can lead to bigger problems — with or without synthetic oil.