Switching from Conventional to Synthetic... - The 1947 - Present Chevrolet & GMC Truck Message Board Network

*MonteSS454* · 04-03-2008, 07:05 AM

Ok, I'm up for an oil change and I want to run synthetic instead of convetional oil.

First off, anything I need to know before switching over and also which brand and weight should I run?

98 Chevy 1500 5.7l Vortech 148k mile.

ProStreet68SB · 04-03-2008, 08:00 AM

Once you go synthetic you should never go back to conventional. Weight wise, you should run w/e you're running now. I'm running synthetic in my s10, and I chose Mobil1.

ed2552 · 04-04-2008, 03:17 AM

You can, it will not hurt anything, but it is nice to run the same stuff. I would recommend either Royal Purple or Mobil 1, i prefer RP, but my dad is stuck on Mobil 1, and it is a good oil as well.

71monteme · 04-04-2008, 05:17 AM

ditto
also i don't change oil until 5000miles intervals.
also mobil 1 here.

*MonteSS454* · 04-04-2008, 07:55 AM

Well I read up on it awhile back and it said I should change it after switching 1500 miles then 2500 miles then the normal 3000.

I ended up putting in Castrol GTX Synthetic Blend 5w-30 today, I'll change it before to long and end up with Royal Purple in it.

Metal · 04-05-2008, 04:06 AM

Try Amsoil http://www.amsoil.com/

ed2552 · 04-05-2008, 05:49 AM

I've never heard that, you change synthetic at 5000 miles, not 3000, that is part of the reason that it is better

Jeep & GMC · 04-05-2008, 06:39 AM

So there is no problem with the detergent properties of synthetic oils stirring up dormant sludge?

ed2552 · 04-05-2008, 07:10 AM

That is the only reason i can see changing it earlier than normal, draining sludge and other stuff the conventional didn't touch

mfarmer · 04-08-2008, 05:16 AM

Switched to synthetic on a 95 Suburban at ~95,000 miles. After about 3000 mile I ended up with a leak on on the oil pan gasket, the oil cooler block between the oil filter and the block and the intake manifold. Coincidence maybe, but after replacing these gaskets I continued to use synthetic with no problem. Moved oil change interval from 3k to 5k. I sold the Sub with 165,000 miles on it and there where no leaks. I currently use mobil 1 on all my vehicles, a 03 1500hd, a 01 jag xjr and a 92 c1500, all with 5k oil change intervals.

Metal · 04-08-2008, 01:28 PM

From what I understand synthetic oil will not cause a leak BUT if there is the slightest leak anywhere it will find it. Because it is much slicker then conventional oil it will poor out...

I have always been told to make sure all the leaks are stopped before you put it in..

I have family members that have been selling Amsoil since the 70's some where around that time anyway..

This stuff is what most folks are running now..http://www.amsoil.com/storefront/Sea...CategoryID=503

Tom · 04-11-2008, 04:48 AM

Quote:

Originally Posted by Metal

From what I understand synthetic oil will not cause a leak BUT if there is the slightest leak anywhere it will find it. Because it is much slicker then conventional oil it will poor out...

I have always been told to make sure all the leaks are stopped before you put it in..

Ditto. Besides alot of people drop the weight they use when switching to syn. I run royal purple in all my familys cars [yeah I have to service all of them] and my trucks. I run it for 6000miles and do a filter change at 3000.

ed2552 · 04-19-2008, 05:37 AM

My dad doesn't want to run RP in our other vehicles, he likes Mobil 1, but he says i can run w/e i want in my tahoe. Just to prove it is better, i'm gonna run M1 this change and next change prove to him that RP is a better oil as far as mileage

Metal · 04-19-2008, 05:41 AM

If you are doing a comparison you need to try the Amsoil...

You will be surprised..All you need to do is google it and read about it compared to M1....

Good luck....

Metal · 04-19-2008, 05:53 AM

I found this..

http://www.amsoil.com/performancetests/g1971/index.aspx

ed2552 · 04-19-2008, 06:10 AM

The nearest place that sells Amsoil is 50 miles away, and that is too far to drive for oil. Napa carries Amsoil near me, but they just keep small engine stuff, they would have to order it, where as Advance and Napa both stock M1 & RP

jgrh64 · 06-07-2008, 09:58 AM

the problem with synthetic blends is you have no way of knowing how much is regular oil and how much is synthetic ! so your paying a premium price for an unknown oil mix. Amsoil royal purple mobile 1 and red line were the originators of synthetics and are premium oils which one is very political so use what you like.

Marv D · 06-08-2008, 10:55 AM

Without bringing up the same ol stories and arguments over and over again..... just be carefull what oil you choose for the type of cam you have. I'm no oil expert, but here's what I do know. ALL oils (conventional or high dollar synthetics) sold over the counter for highway use (that have the API starburst), have to meet current Federal/EPA standards, and have reduced the wear additives. If your running a pre95 motor with a flat tappet cam, consider an additive or at least a couple of quarts of 'off road' race oil per oil change. And be cautious, the stuff sold over the counter like Valvoline VR1 "race oil", and Royal Purple sold in the discount parts places like Autozone / Pep Boys, CSK are NOT a off-road oil and do NOT have the additive packages (including higher contents of ZDDP) of a real race oil like Royal Purple XRP -21, 41 or whatever. I hate to put it this way because you can still get screwed, but you can generally tell a real off road only race oil by the price,, about $13+ a quart vs a street oil around $6-7 a qt. Also be aware, many off road race oils have dramatically reduced detergent properties compared to over the counter EPA oils. You don't leave this stuff in for 5000 miles

It's that same ol problem... your motor needs that extra protection of a offroad oil, your gonna pay dearly for it!

Lots of people who change their high milage engines from conventional dino oil to synthetics complain of oil seal leakage, and new leaks. It's the very properties that makes synthetics a better choice, that makes it find the leaks. If it was a slight 'weep' with dino oil, it will be a 'leak' with the lighter viscosities of synthetics,, if it was a leak, before, it's safe to expect it to be a bigger leak with synthetics.

jgrh and I are of the same mind when it comes to synthetic blends. It's SNAKE OIL!!! Don't waste your money on it!
My suggestion,,, at a hundred and xxxxx thousand miles, there is really not a lot of advantage to switching to a synthetic. With oil clearances being what they are in a high milage motor, the heavier viscosities / larger molecules in a conventional dino oil may actually be a better choice.

just my 2cents

04-03-2008, 07:05 AM	#1
MonteSS454 Account Suspended Join Date: Jun 2007 Location: Claremore, Oklahoma Posts: 821	Switching from Conventional to Synthetic... Ok, I'm up for an oil change and I want to run synthetic instead of convetional oil. First off, anything I need to know before switching over and also which brand and weight should I run? 98 Chevy 1500 5.7l Vortech 148k mile.

04-03-2008, 08:00 AM	#2
ProStreet68SB The Engine Whisperer Join Date: Sep 2006 Location: Ohio Posts: 770	Re: Switching from Conventional to Synthetic... Once you go synthetic you should never go back to conventional. Weight wise, you should run w/e you're running now. I'm running synthetic in my s10, and I chose Mobil1.

04-04-2008, 03:17 AM	#3
ed2552 Registered User Join Date: Jan 2007 Location: Charles City IA Posts: 1,626	Re: Switching from Conventional to Synthetic... You can, it will not hurt anything, but it is nice to run the same stuff. I would recommend either Royal Purple or Mobil 1, i prefer RP, but my dad is stuck on Mobil 1, and it is a good oil as well. __________________ '67 C20, Under the Knife!, LWB, Eaton HO-52, Rear Coil Springs 72' GMC C2500, 350, TH400(?), Dana 60 '67 K10 4-spd., 305, SM465, Dana 44, 12 Bolt, RUST! '65 C60 292, 4 spd, 2 spd Rearend, 15' Grain Box, MINT! 09 Yukon Denali 82k Miles 6.2L/6A

04-04-2008, 05:17 AM	#4
71monteme Registered User Join Date: Feb 2004 Location: New Britain, CT Posts: 70	Re: Switching from Conventional to Synthetic... ditto also i don't change oil until 5000miles intervals. also mobil 1 here.

04-04-2008, 07:55 AM	#5
MonteSS454 Account Suspended Join Date: Jun 2007 Location: Claremore, Oklahoma Posts: 821	Re: Switching from Conventional to Synthetic... Well I read up on it awhile back and it said I should change it after switching 1500 miles then 2500 miles then the normal 3000. I ended up putting in Castrol GTX Synthetic Blend 5w-30 today, I'll change it before to long and end up with Royal Purple in it.

04-05-2008, 04:06 AM	#6
Metal Registered User Join Date: Mar 2008 Location: tn Posts: 286	Re: Switching from Conventional to Synthetic... Try Amsoil http://www.amsoil.com/ __________________ "If at first you don't succeed use more duct tape" Red Green.... Danger --if you meet it promptly and without flinching -- you will reduce the danger by half. Never run away from anything. Never! -Winston Churchill A few of my holsters.............

04-05-2008, 05:49 AM	#7
ed2552 Registered User Join Date: Jan 2007 Location: Charles City IA Posts: 1,626	Re: Switching from Conventional to Synthetic... I've never heard that, you change synthetic at 5000 miles, not 3000, that is part of the reason that it is better __________________ '67 C20, Under the Knife!, LWB, Eaton HO-52, Rear Coil Springs 72' GMC C2500, 350, TH400(?), Dana 60 '67 K10 4-spd., 305, SM465, Dana 44, 12 Bolt, RUST! '65 C60 292, 4 spd, 2 spd Rearend, 15' Grain Box, MINT! 09 Yukon Denali 82k Miles 6.2L/6A

04-05-2008, 06:39 AM	#8
Jeep & GMC Registered User Join Date: Aug 2007 Location: Montrose,CO Posts: 172	Re: Switching from Conventional to Synthetic... So there is no problem with the detergent properties of synthetic oils stirring up dormant sludge?

04-05-2008, 07:10 AM	#9
ed2552 Registered User Join Date: Jan 2007 Location: Charles City IA Posts: 1,626	Re: Switching from Conventional to Synthetic... That is the only reason i can see changing it earlier than normal, draining sludge and other stuff the conventional didn't touch __________________ '67 C20, Under the Knife!, LWB, Eaton HO-52, Rear Coil Springs 72' GMC C2500, 350, TH400(?), Dana 60 '67 K10 4-spd., 305, SM465, Dana 44, 12 Bolt, RUST! '65 C60 292, 4 spd, 2 spd Rearend, 15' Grain Box, MINT! 09 Yukon Denali 82k Miles 6.2L/6A

04-08-2008, 05:16 AM	#10
mfarmer Registered User Join Date: Sep 2006 Location: Georgetown, Texas Posts: 97	Re: Switching from Conventional to Synthetic... Switched to synthetic on a 95 Suburban at ~95,000 miles. After about 3000 mile I ended up with a leak on on the oil pan gasket, the oil cooler block between the oil filter and the block and the intake manifold. Coincidence maybe, but after replacing these gaskets I continued to use synthetic with no problem. Moved oil change interval from 3k to 5k. I sold the Sub with 165,000 miles on it and there where no leaks. I currently use mobil 1 on all my vehicles, a 03 1500hd, a 01 jag xjr and a 92 c1500, all with 5k oil change intervals.

04-08-2008, 01:28 PM	#11
Metal Registered User Join Date: Mar 2008 Location: tn Posts: 286	Re: Switching from Conventional to Synthetic... From what I understand synthetic oil will not cause a leak BUT if there is the slightest leak anywhere it will find it. Because it is much slicker then conventional oil it will poor out... I have always been told to make sure all the leaks are stopped before you put it in.. I have family members that have been selling Amsoil since the 70's some where around that time anyway.. This stuff is what most folks are running now..http://www.amsoil.com/storefront/Sea...CategoryID=503 __________________ "If at first you don't succeed use more duct tape" Red Green.... Danger --if you meet it promptly and without flinching -- you will reduce the danger by half. Never run away from anything. Never! -Winston Churchill A few of my holsters.............

04-19-2008, 05:37 AM	#13
ed2552 Registered User Join Date: Jan 2007 Location: Charles City IA Posts: 1,626	Re: Switching from Conventional to Synthetic... My dad doesn't want to run RP in our other vehicles, he likes Mobil 1, but he says i can run w/e i want in my tahoe. Just to prove it is better, i'm gonna run M1 this change and next change prove to him that RP is a better oil as far as mileage __________________ '67 C20, Under the Knife!, LWB, Eaton HO-52, Rear Coil Springs 72' GMC C2500, 350, TH400(?), Dana 60 '67 K10 4-spd., 305, SM465, Dana 44, 12 Bolt, RUST! '65 C60 292, 4 spd, 2 spd Rearend, 15' Grain Box, MINT! 09 Yukon Denali 82k Miles 6.2L/6A

04-19-2008, 05:41 AM	#14
Metal Registered User Join Date: Mar 2008 Location: tn Posts: 286	Re: Switching from Conventional to Synthetic... If you are doing a comparison you need to try the Amsoil... You will be surprised..All you need to do is google it and read about it compared to M1.... Good luck.... __________________ "If at first you don't succeed use more duct tape" Red Green.... Danger --if you meet it promptly and without flinching -- you will reduce the danger by half. Never run away from anything. Never! -Winston Churchill A few of my holsters.............

04-19-2008, 05:53 AM	#15
Metal Registered User Join Date: Mar 2008 Location: tn Posts: 286	Re: Switching from Conventional to Synthetic... I found this.. http://www.amsoil.com/performancetests/g1971/index.aspx __________________ "If at first you don't succeed use more duct tape" Red Green.... Danger --if you meet it promptly and without flinching -- you will reduce the danger by half. Never run away from anything. Never! -Winston Churchill A few of my holsters.............

04-19-2008, 06:10 AM	#16
ed2552 Registered User Join Date: Jan 2007 Location: Charles City IA Posts: 1,626	Re: Switching from Conventional to Synthetic... The nearest place that sells Amsoil is 50 miles away, and that is too far to drive for oil. Napa carries Amsoil near me, but they just keep small engine stuff, they would have to order it, where as Advance and Napa both stock M1 & RP __________________ '67 C20, Under the Knife!, LWB, Eaton HO-52, Rear Coil Springs 72' GMC C2500, 350, TH400(?), Dana 60 '67 K10 4-spd., 305, SM465, Dana 44, 12 Bolt, RUST! '65 C60 292, 4 spd, 2 spd Rearend, 15' Grain Box, MINT! 09 Yukon Denali 82k Miles 6.2L/6A



Register or Log In To remove these advertisements.

06-07-2008, 09:58 AM	#17
jgrh64 Prestige member Old Farts Club Join Date: Nov 2005 Location: Cleveland Posts: 502	Re: Switching from Conventional to Synthetic... the problem with synthetic blends is you have no way of knowing how much is regular oil and how much is synthetic ! so your paying a premium price for an unknown oil mix. Amsoil royal purple mobile 1 and red line were the originators of synthetics and are premium oils which one is very political so use what you like. __________________ Hey sombodys gotta do it!

06-08-2008, 10:55 AM	#18
Marv D Registered Truck Offender Join Date: May 2008 Location: hells training ground (aka Ariz) Posts: 3,121	Re: Switching from Conventional to Synthetic... Without bringing up the same ol stories and arguments over and over again..... just be carefull what oil you choose for the type of cam you have. I'm no oil expert, but here's what I do know. ALL oils (conventional or high dollar synthetics) sold over the counter for highway use (that have the API starburst), have to meet current Federal/EPA standards, and have reduced the wear additives. If your running a pre95 motor with a flat tappet cam, consider an additive or at least a couple of quarts of 'off road' race oil per oil change. And be cautious, the stuff sold over the counter like Valvoline VR1 "race oil", and Royal Purple sold in the discount parts places like Autozone / Pep Boys, CSK are NOT a off-road oil and do NOT have the additive packages (including higher contents of ZDDP) of a real race oil like Royal Purple XRP -21, 41 or whatever. I hate to put it this way because you can still get screwed, but you can generally tell a real off road only race oil by the price,, about $13+ a quart vs a street oil around $6-7 a qt. Also be aware, many off road race oils have dramatically reduced detergent properties compared to over the counter EPA oils. You don't leave this stuff in for 5000 miles It's that same ol problem... your motor needs that extra protection of a offroad oil, your gonna pay dearly for it! Lots of people who change their high milage engines from conventional dino oil to synthetics complain of oil seal leakage, and new leaks. It's the very properties that makes synthetics a better choice, that makes it find the leaks. If it was a slight 'weep' with dino oil, it will be a 'leak' with the lighter viscosities of synthetics,, if it was a leak, before, it's safe to expect it to be a bigger leak with synthetics. jgrh and I are of the same mind when it comes to synthetic blends. It's SNAKE OIL!!! Don't waste your money on it! My suggestion,,, at a hundred and xxxxx thousand miles, there is really not a lot of advantage to switching to a synthetic. With oil clearances being what they are in a high milage motor, the heavier viscosities / larger molecules in a conventional dino oil may actually be a better choice. just my 2cents __________________ Still playin with trucks, even at my age! When you're dead, it's only a problem for the people around you, because you don't know you're dead. .....It's kinda the same when your STUPID. I just did my taxes and reviewed my SS statement. Thanks to the current administration it looks like I will only have to work till noon on the day of my funeral.

Register or Log In To remove these advertisements.