# Synthetic or not to Synthetic **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** chevrolet, tahoe, engines, oil\ **Created:** [September 29, 2020, 12:39pm UTC](https://community.cartalk.com/t/synthetic-or-not-to-synthetic/170598 "2020-09-29T12:39:35Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![glennst1011\_160276](https://avatars.discourse-cdn.com/v4/letter/g/8baadc/32.png) [@glennst1011\_160276](https://community.cartalk.com/u/glennst1011_160276)\ **Post date:** [September 29, 2020, 12:39pm UTC](https://community.cartalk.com/t/synthetic-or-not-to-synthetic/170598/1 "2020-09-29T12:39:35Z")
I have had a remanufactured motor installed in my 2004 Tahoe. (Kept my old motor for project). Anyway the shop gave me a directions sheet and it states to change oil at 500 miles but NOT to use synthetic oil. Then go 3000 miles and then I can use synthetic if I prefer. I have not called the shop yet but curious if anyone understands the reason for this guidance ? ---
**Author:** ![VOLVO-V70](https://avatars.discourse-cdn.com/v4/letter/v/8e8cbc/32.png) [@VOLVO-V70](https://community.cartalk.com/u/VOLVO-V70)\ **Post date:** [September 29, 2020, 12:58pm UTC](https://community.cartalk.com/t/synthetic-or-not-to-synthetic/170598/2 "2020-09-29T12:58:38Z")
> [@glennst1011\_160276](#): > > I have not called the shop yet but curious if anyone understands the reason for this guidance ? That is what the shop says to do . They are the ones who will handle what warranty problems you might have . What more reason do you need ? And yes you should let the shop explain it for you. There are very good mechanics that post here but if I gave you conflicting advice how would you even know if I knew what I was talking about. Edit - don’t know what the warranty is on this engine but if the shop does oil and filter changes I would have them do the changes during the warranty period . ---
**Author:** ![tcmichnorth](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tcmichnorth/32/25126_2.png) [@tcmichnorth](https://community.cartalk.com/u/tcmichnorth)\ **Post date:** [September 29, 2020, 1:02pm UTC](https://community.cartalk.com/t/synthetic-or-not-to-synthetic/170598/3 "2020-09-29T13:02:53Z")
Synthetic oils lubricate more efficiently. He wants you to use regular oil to help the rings seal to the cylinder walls. It is a break in procedure. ---
**Author:** ![Mustangman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mustangman/32/44130_2.png) [@Mustangman](https://community.cartalk.com/u/Mustangman)\ **Post date:** [September 29, 2020, 1:51pm UTC](https://community.cartalk.com/t/synthetic-or-not-to-synthetic/170598/4 "2020-09-29T13:51:15Z")
> [@tcmichnorth](#): > > use regular oil to help the rings seal to the cylinder walls. It is a break in procedure That is the reason right there… ---
**Author:** ![glennst1011\_160276](https://avatars.discourse-cdn.com/v4/letter/g/8baadc/32.png) [@glennst1011\_160276](https://community.cartalk.com/u/glennst1011_160276)\ **Post date:** [September 29, 2020, 2:13pm UTC](https://community.cartalk.com/t/synthetic-or-not-to-synthetic/170598/5 "2020-09-29T14:13:55Z")
Thanks tcmichnorth and mustangman for the info. This is exactly what I was curious about. Volvo-V70 really? Cmon really? If you don’t know just pass. I don’t need to hear something I already know. “cause that is what the shop said to do” ? ---
**Author:** ![MikeInNH](https://avatars.discourse-cdn.com/v4/letter/m/a587f6/32.png) [@MikeInNH](https://community.cartalk.com/u/MikeInNH)\ **Post date:** [September 29, 2020, 2:53pm UTC](https://community.cartalk.com/t/synthetic-or-not-to-synthetic/170598/6 "2020-09-29T14:53:01Z")
> [@tcmichnorth](#): > > Synthetic oils lubricate more efficiently. He wants you to use regular oil to help the rings seal to the cylinder walls. It is a break in procedure. Auto manufacturers must do a different process because new vehicles will be delivered with synthetic oil…normal oil that vehicle is suppose to use as outlined in owners manual. I haven’t seen a new engine with break-in oil for any special oil for the break-in period for decades. ---
**Author:** ![tcmichnorth](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tcmichnorth/32/25126_2.png) [@tcmichnorth](https://community.cartalk.com/u/tcmichnorth)\ **Post date:** [September 29, 2020, 3:01pm UTC](https://community.cartalk.com/t/synthetic-or-not-to-synthetic/170598/7 "2020-09-29T15:01:28Z")
With later model cars the machining tolerances have greatly improved making a wear in break in unnecessary. ---
**Author:** ![MikeInNH](https://avatars.discourse-cdn.com/v4/letter/m/a587f6/32.png) [@MikeInNH](https://community.cartalk.com/u/MikeInNH)\ **Post date:** [September 29, 2020, 3:02pm UTC](https://community.cartalk.com/t/synthetic-or-not-to-synthetic/170598/8 "2020-09-29T15:02:58Z")
> [@tcmichnorth](#): > > With later model cars the machining tolerances have greatly improved making a wear in break in unnecessary This 2004 Tahoe should fall well in what’s considered a late model. All I can assume is the builder can’t build to the same tolerances the manufacturer can. ---
**Author:** ![Mustangman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mustangman/32/44130_2.png) [@Mustangman](https://community.cartalk.com/u/Mustangman)\ **Post date:** [September 29, 2020, 3:10pm UTC](https://community.cartalk.com/t/synthetic-or-not-to-synthetic/170598/9 "2020-09-29T15:10:15Z")
> [@MikeInNH](#): > > I can assume is the builder can’t build to the same tolerances the manufacturer can. I think this is the correct reason. There may be a bit of… “This what we have always recommended” as well. ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [September 29, 2020, 3:16pm UTC](https://community.cartalk.com/t/synthetic-or-not-to-synthetic/170598/10 "2020-09-29T15:16:40Z")
> **[Engine Break-In Guide: 10 Tips to Help Properly Break in Your Engine -...](https://www.onallcylinders.com/2014/11/13/engine-break-guide-10-tips-help-properly-break-engine/)** > > Proper engine break-in procedure is critical. The right steps during this procedure can save your engine, your bank account, and ultimately your sanity. With help from the engine experts at ATK High Performance Engines … Tester ---
**Author:** ![MikeInNH](https://avatars.discourse-cdn.com/v4/letter/m/a587f6/32.png) [@MikeInNH](https://community.cartalk.com/u/MikeInNH)\ **Post date:** [September 29, 2020, 3:20pm UTC](https://community.cartalk.com/t/synthetic-or-not-to-synthetic/170598/11 "2020-09-29T15:20:30Z")
> [@Mustangman](#): > > I think this is the correct reason. There may be a bit of… “This what we have always recommended” as well. This makes sense…or the manufacturer is somehow doing a break-in before they are shipped. I’m sure a good builder knows what they’re doing…I’m just curious why. ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [September 29, 2020, 3:33pm UTC](https://community.cartalk.com/t/synthetic-or-not-to-synthetic/170598/12 "2020-09-29T15:33:03Z")
I think most/all rebuilders are using very different equipment to grind, hone, and set clearances than the manufacturers, so I’m not surprised that the break in instructions are different.