Which Synth yields best results in 5.3l GM truck?

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Originally Posted By: NHSilverado
Originally Posted By: beatle78
Originally Posted By: beatle78
Originally Posted By: NHSilverado


NHSilverado, Can you elaborate? What do you mean by the engines "loved it"?

What differences did you notice with the Royal Purple?

Thanks,
beatle78


Smoother idle and acceleration, less engine noise overall but especially at cold startup which is an issue for GM 5.3L's( especially older ones like yours ), and a slight MPG improvement( approc .2-.5 MPG city and highway ).


ok, NICE!

I noticed my truck (which I've owned for ~3 weeks) does have a little bit of a rough idle. It only has 36k miles.

I have read reports about piston slap on cold startups.

Did you gain the .5 mpg highway with just RP motor oil, or with RP tranny and RP diff fluid as well?


The gains I mentioned were based soley on the oil as that is what you asked about. I did swap both Silverado's over to RP's gear oil as welll( MaxGear 75W-90 in both front and rear dif's on both trucks ). That bumped the MPG higher( over 1 MPG highway gain ). Never used the RP MaxATf in the trucks although I have used it before and it is great stuff.

If you have a rough idle now the oil isn't going to fix it. It just smoothes out a standard idle further.


ok, thanks. I guess the idle isn't ruff, there is a slight hessitation occasionally, but after more reading on fullsizechevy.com it seems like that is normal.

I LIKE the 1 MPG gain with the synthetic diff fluids. Is that 1 MPG more than the .5 mpg gain from the oil, or is it a 1mpg total (oil + diff)

My truck came with synthetic diff fluid in the rear(according to the window sticker). I wonder if synthetic in the front will make a difference in mpg.
 
If you haven't serviced the front diff yet do it...they wear more than you think! Wait til you pull out the magnetic drain plug and it looks like it has an afro from the numerous metal shavings that accumulate on it...it's a little unsettling.
 
Originally Posted By: beatle78


ok, thanks. I guess the idle isn't ruff, there is a slight hessitation occasionally, but after more reading on fullsizechevy.com it seems like that is normal.

I LIKE the 1 MPG gain with the synthetic diff fluids. Is that 1 MPG more than the .5 mpg gain from the oil, or is it a 1mpg total (oil + diff)

My truck came with synthetic diff fluid in the rear(according to the window sticker). I wonder if synthetic in the front will make a difference in mpg.


It was 1 MPG overall. If you swap the tranny over as well you may see upwards of 2 MPG total gain( with proper tire inflation ). I know many guys on the Chevy truck forums that did this and saw up to a 2 MPG gain.

If you have the Eaton G80 rear diff, then yes, it came with 75W-90 synthetic. The GM syntheitc 75W-90 gear lube is not all that great and it is extremely expensive. RP's MaxGear is a vastly superior product in my experience and opinion. The front diff calls for conventional 80W-90. I always swap to the MaxGear 75W-90 and it works great. As another poster mentioned get that front fluid changed if you aren't sure it has been done.
 
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Originally Posted By: firemachine69
Originally Posted By: tpitcher

Oh yea, since you are talking MPG's, I get 18.5 MPG at 75 MPH and 22-23 MPG at 55-60 on my 5.3L with 129,000 miles on it......



I hope you don't drive too much... Ouch.



Ouch what? Those are great numbers for a V8 in a truck thats likely well over 4,000 pounds. GM is top dog in fuel mileage and power in there trucks.
 
Originally Posted By: ProStreetCamaro
Originally Posted By: firemachine69
Originally Posted By: tpitcher

Oh yea, since you are talking MPG's, I get 18.5 MPG at 75 MPH and 22-23 MPG at 55-60 on my 5.3L with 129,000 miles on it......



I hope you don't drive too much... Ouch.



Ouch what? Those are great numbers for a V8 in a truck thats likely well over 4,000 pounds. GM is top dog in fuel mileage and power in there trucks.

yup GM trucks get pretty good mileage,mine does.
 
Originally Posted By: NHSilverado

It was 1 MPG overall. If you swap the tranny over as well you may see upwards of 2 MPG total gain( with proper tire inflation ). I know many guys on the Chevy truck forums that did this and saw up to a 2 MPG gain.

If you have the Eaton G80 rear diff, then yes, it came with 75W-90 synthetic. The GM syntheitc 75W-90 gear lube is not all that great and it is extremely expensive. RP's MaxGear is a vastly superior product in my experience and opinion. The front diff calls for conventional 80W-90. I always swap to the MaxGear 75W-90 and it works great. As another poster mentioned get that front fluid changed if you aren't sure it has been done.


OK, I will def change over the front diff soon, and I'll do the rear end as well since I'm there.

The truck only has 36k miles on it so I think doing it now should ad lots of life/protection to both diffs....
 
Well tecnicaly your engine does not require 5W30 that is merly a recomendation. RP is bloated hype and not the best product for your dollar! Rotella T Synthetic 5W40 is about as good as it is going to get for you. $16 a gallon at Walmart. I doubt you find any oil at any price that is going to do a better job in your application! My next choice would be M1 0W40 then M1 High Milage 10W30. If have to have 5W30 in order to sleep at nights I would go with either Redline 5W30,Amsoil Seires 3000 5W30, Synergen 3W30 LTS and last but not least NEO 5W30. If you go with Redline or NEO do at least two OCI before you consider sampleing for UOA so that would mean three total OCI's witht he same product both Redline and Neo are Ester based and they do some significant scouring of oxidized alloys and left over wear metals.
 
Originally Posted By: JohnBrowning
Well tecnicaly your engine does not require 5W30 that is merly a recomendation. RP is bloated hype and not the best product for your dollar! Rotella T Synthetic 5W40 is about as good as it is going to get for you. $16 a gallon at Walmart. I doubt you find any oil at any price that is going to do a better job in your application! My next choice would be M1 0W40 then M1 High Milage 10W30. If have to have 5W30 in order to sleep at nights I would go with either Redline 5W30,Amsoil Seires 3000 5W30, Synergen 3W30 LTS and last but not least NEO 5W30. If you go with Redline or NEO do at least two OCI before you consider sampleing for UOA so that would mean three total OCI's witht he same product both Redline and Neo are Ester based and they do some significant scouring of oxidized alloys and left over wear metals.



John,

Thanks for weighing in. I'm digesting what you said!

You are right, I'm scared to put a 40W oil in my truck. Maybe I'll come around, but could you explain why you think a 40W oil is OK in my engine?

That Rotella T seems like a good deal. I use Rotella T 15W-40 dino in my 5.7L marine engine.

I've also been considering the PP since it seems to get good reviews on this forum.

As I have time to do some more research I will bounce some other questions off of you.

I do need to change my oil by this weekend and I already have the Napa Gold filter, but I need to choose an oil for this first change to synthetic ASAP. Perhaps I'll go to Advance Auto Parts where the PP is on sale for $3.98 right now.
 
John,

I just realized a lot of oils you recommended (including the Amsoil series 3000 5W-30) are HD diesel oils.

What is ti about the diesel oils that you like in the gasoline engines?

Thanks!
beatle78
 
FYI,

Advances Auto Parts has PP on sale for $3.98/qt this week!!

I didn't realize the "normal" price was $6.19/qt OUCH!!!

I picked up 6 qts last night since I need to change my oil ASAP!

I still have not made a long term decision yet.
 
Originally Posted By: beatle78
FYI,

Advances Auto Parts has PP on sale for $3.98/qt this week!!

I didn't realize the "normal" price was $6.19/qt OUCH!!!

I picked up 6 qts last night since I need to change my oil ASAP!

I still have not made a long term decision yet.


WalMart sells PP in 5 quart jugs for $18.97 everyday... roughly $3.79 per quart.
 
I had a 5.3 in a Suburban I traded last year. I ran Schaeffer's #703(10W30) for a time and later I ran German Castrol(0W30). IMO, the GC did a good job, but the Schaeffer's did a great job. Stayed in grade better and oxidation levels were better.

I vote Schaeffer's 7000 series or 9000 series.
 
Originally Posted By: beatle78
John,

I just realized a lot of oils you recommended (including the Amsoil series 3000 5W-30) are HD diesel oils.

What is ti about the diesel oils that you like in the gasoline engines?

Thanks!
beatle78


Diesel oils tend to have a better add pack meaning they have more anti wear additives. They are designed for maximum protection because most people who buy a diesel buy it for heavy duty hauling and towing. A normal car engine will not ever see the stress that gets put on diesel engines. I know alot of people that loce rotella syn in there gas engines. Very good results from it.

Our new 2500HD with the 6.0 now has a little over 700 miles. At 800 or so i will do the break in oil change with yellow bottle penz. I will take that out to 1500 or 200 miles then switch to either PP or rotella syn (most likely rotella syn will be my choice)
 
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Originally Posted By: ProStreetCamaro
Originally Posted By: beatle78
John,

I just realized a lot of oils you recommended (including the Amsoil series 3000 5W-30) are HD diesel oils.

What is ti about the diesel oils that you like in the gasoline engines?

Thanks!
beatle78


Diesel oils tend to have a better add pack meaning they have more anti wear additives. They are designed for maximum protection because most people who buy a diesel buy it for heavy duty hauling and towing. A normal car engine will not ever see the stress that gets put on diesel engines. I know alot of people that loce rotella syn in there gas engines. Very good results from it.

Our new 2500HD with the 6.0 now has a little over 700 miles. At 800 or so i will do the break in oil change with yellow bottle penz. I will take that out to 1500 or 200 miles then switch to either PP or rotella syn (most likely rotella syn will be my choice)



Also, since they are designed to resist the dilution/blowby/shear? inherent in most oil burners, the HD diesel oils usually have a VERY high starting TBN, and also sustain that TBN better than most gas engine oriented oils over the OCI period.
 
Originally Posted By: dailydriver
Also, since they are designed to resist the dilution/blowby/shear? inherent in most oil burners, the HD diesel oils usually have a VERY high starting TBN, and also sustain that TBN better than most gas engine oriented oils over the OCI period.

Sorry for the O/T, but I've wondered whether an oil with a super high TBN is PH neutral in its virgin state.
 
In my '04 Sierra 5.3L I've tried Chevron Supreme, Mobil Clean 5000, PP and GC. Having done a few UOA's in my 67,000 miles, I'm thrilled with the performance of GC and PP. The Mobil stuff generated too much CSK/piston slap for me and I won't use another Mobil product again in this truck. The PP and GC have kept CSK to a minimum. Both have performed very well although I'm sticking with GC while it's available.

Personally I feel these GM Vortec modular engines like a slightly higher vis oil. GC is close to a 40W yet still has the low temp pump-ability I want for max flow and protection at startup.

I've also run various 10W-30's in service trucks and vans with the 4.8L and 6.0L with no problems. Keep in mind I'm in Georgia where dealing with the heat and humidity is more of an issue than the cold, although it does occasionally drop into the 20's and 30's in the winter.

If you want to stick with one oil that's readily available at retail, PP would be my recommendation.
 
Originally Posted By: bretfraz
In my '04 Sierra 5.3L I've tried Chevron Supreme, Mobil Clean 5000, PP and GC. Having done a few UOA's in my 67,000 miles, I'm thrilled with the performance of GC and PP. The Mobil stuff generated too much CSK/piston slap for me and I won't use another Mobil product again in this truck. The PP and GC have kept CSK to a minimum. Both have performed very well although I'm sticking with GC while it's available.

Personally I feel these GM Vortec modular engines like a slightly higher vis oil. GC is close to a 40W yet still has the low temp pump-ability I want for max flow and protection at startup.

I've also run various 10W-30's in service trucks and vans with the 4.8L and 6.0L with no problems. Keep in mind I'm in Georgia where dealing with the heat and humidity is more of an issue than the cold, although it does occasionally drop into the 20's and 30's in the winter.

If you want to stick with one oil that's readily available at retail, PP would be my recommendation.


If the GC oil is close to 40W, then the recomendation to use Rotella T Synthetic 5W40, would be OK?

BTW, what is GC oil? [EDIT: GERMAN CASTROL]
 
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Since no one has said it yet, I will...

Get an oil analysis. You don't have to do it now, but do it.

I have a 5.3L Tahoe. I have used Amsoil, M1 0W30, 5W30, 5W30EP, and PP over the 7 years that I have owned this truck.

My results are backed by used oil analysis.

What works for me in Colorado, may not work for you in RI. That is why you need an oil analysis.

One cannot "feel" fuel dilution. One cannot "sense" if the air filter is blowing dirt into your oil.

I use PP, and feel it is a good oil. I did not have satisfactory result with the other oils.

My triboligist (Terry Dyson) has recommended that I go with the BioSyn. I'll give that a try. No real reason other than it makes my engine feel good.
 
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