I hate this... oil isn't oil and it's been debated to the ends of the earth.

However... I have been religious about using 5-30 Mobil 1 in my Vette... alas, it is nearing 180k miles and I am wondering if it isn't a bad idea to upgrade to maybe 15-50?

Engine gurus, thoughts?

What is your oil pressure doing? What is it at idle when cold, idle when hot, and then at various RPM ranges, both when cold and when hot?

If your tolerances were opening up too much from high mileage wear, you'd start seeing a steady decrease in your oil pressure on one or several of the fronts listed above.

You can also split the type pf oil you use by season. In cold months, run 5-30. In hot months, run something a tad thicker.

Quote:

I agree with Matt.

But, also, I ran a SBC to 250k on dyno oil before it need rebuilding and never changed the viscosity.

And I've never been concerned about hot idle pressure unless the other pressures are out of spec.

If you really want to know, put a real OP gauge on the motor. If you want to experiment, put the 15-50 in and gauge it again.

But don't put in Mobil High Milage oil.

Yeah, really depends on your hot and cold oil temps.

15w is pretty thick on a cold engine, I always wondered if the high pressure meant it was bypassing the oil filter.

Now that I'm adding this zddp stuff to it which is like molasses I'm going to have to find a thinner oil. I wonder if they make 10-40 anymore.

Any oil consumption?
I like 10w30. Less viscosity enhancers means less viscosity breakdown over time.
http://www.upmpg.com/tech_articles/motoroil_viscosity/

I would think the 10w30 would be your best option. I know some guys recommend putting 2 qts of 10-30 and the rest 5w30 to help with the piston slap in the LS engines....thought I might try that....

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Why? Does it damage the seals?

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Donno, Kevin.
My only experience was, I put it in my Silverado - 5.3 Vortec at approx. 125k miles. It started to smoke (big puff) on startup. I ran 1.5k and went back to 5-30 M1, the smoke on start up went away after a couple hundred miles.

Certainly not scientific and I've no idea why it happened.
But it's enough for me not to use it again.
I have zero problems with M1 syn. so I guess, if it ain't broke, don't zix it.

I am getting low readings on the OP gauge... the problem with the readings is that they started to go low after I replaced the sensor! So I do need to put a real gauge on there.

No burn that I can see/smell.

At the risk of causing some criticism I will tell you what I was running in my hi mileage LT1. Every oil change it got 4 qts Mobile One 5W30 and a quart of Lucas Oil Stabilizer. When I pulled the engine at 227,000 it was still running strong and burning no oil.

Andy, my oil pressure sender read high for so long... 40-80psi.

When I cleaned the gunk out of the sensor, it started reading much lower. I've even hit 15psi at hot idle. Seems like the crud was pushing on the sensor, yet it read close to zero with the engine off.

all my readings are between 20-40 psi with this current sensor.

Hot idle is just a little below. I did the oil cap test and found flow, and the engine isn't running hot, so it's getting oil.

i personally always like 5w40 i think mobile 1 makes the stuff too. just my preference but atm i am using 5w30 myself.

it's think when it's cold at start up and it thickens up just a tad when it gets really warm.

High teens sounds fine to me. Keep in mind that is at idle, when there's hardly any load on the bearings. Now at 2500+ rpm, when you do, the oil pressure will be up already.

Min. pressure-
6psi @ 1,000 rpm
18 @ 2,000
24 @ 4,000

Living in SoCal I don't think it'll ever get cold enough to cause problems even running 20W50 - if you wanted to.... but honestly with the oil pressure your seeing there is really no need to change anything.
Will

Figured as much... but wanted to be sure.

Thanks guys!

Do a 20 dollar Oil Analysis from Blackstone. It will tell you whats happening within the engine.
I surf bobstheoilguy website. i need a drink after talking oil there. Shell Rotella 15w40 is a great oil with high ZDDP, Mobil 10w30 will probably be fine. So many articles on oil, temps, etc etc.
at 110000 miles on my LT1 that used Mobil 1 still had cross hatch marks in the cylinders.
http://www.blackstone-labs.com/free-test-kits.php

Shell Rotella with high zddp levels is a thing of the past.

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True, but their levels are much higher than other brands of oils. I got ahold of Shell. Remember the oil is a diesel oi, so it has to meet different specs on the zddp. It still has high levels, just not as high as they used too.
here is a good thread on some oils with high zddp
http://www.bobistheoilguy.com/forums/ ... p&Search=true#Post2405532
Mobil 1 extended has 20% more ZDDP, 1000ppm vs 800ppm than regular mobil 1.

From BITOG's web site:

Name Vis P (ppm) Zn (ppm) B (ppm) Detergents (ppm) API
Date Type Source

Amerilube 10w50 1254 1115 3001 SL 04/07 SYN Blackstone

Amsoil AFL Euro 5w40 701 804 50 1452 SL 11/06 SYN Staveley

Amsoil HDEO 5w40 794 1081 2276 CJ-4 11/06 SYN Staveley

Amsoil Series 2000 Racing 20w50 1014 1123 12 3209 SM 02/07 SYN
Blackstone

Amsoil V-Twin/MC 20w50 1193 1281 3564 SJ 11/05 SYN Staveley

Amsoil XL-7500 5w20 434 532 165 1601 SL 08/06 SEMI Blackstone

Amsoil XL-7500 5w20 334 1096 209 3061 SL 06/06 SEMI Staveley


Castrol Act Evo 20w50 765 1126 1724 SG 05/06 DINO Staveley

Castrol GPS 4STK MC2 20w50 767 1133 1544 SG 05/06 SYN Staveley

Castrol GTX 20w50 1157 1422 1848 SM 11/05 DINO Staveley

Castrol GTX High Mile 20w50 1248 1382 1848 SM 06/06 DINO Staveley

Castrol Syntec 5w40 786 918 1979 SL 09/06 SYN Blackstone

Castrol Syntec 5w50 921 914 58 2628 SM 11/05 SYN Staveley

Castrol Syntec Blend 20w50 937 916 1197 SM 03/07 SEMI Staveley

Castrol Tection Extra 15w40 965 1094 46 2461 CI-4 3/07 DINO Blackstone

Castrol TWS 10w60 425 1294 111 2383 SJ 06/06 SYN Staveley

Chevron Delo 400 15w40 1191 1622 3668 CI-4 06/06 DINO Staveley

Delvac 1 5w40 1390 1803 76 2583 CI-4 11/05 SYN Staveley

Delvac 1300 Super 15w40 1380 1702 78 2388 CI-4 11/05 DINO Staveley

Elf 505.01 VW 5w40 584 1092 2691 SL 05/06 SYN Staveley

Exxon Av Break-in oil 20w50 1 4 23 N/A 11/05 DINO Staveley

Exxon Av Oil 20w50 702 32 33 N/A 11/05 SEMI Staveley

Exxon Superflow 20w50 717 848 96 2650 SM 06/06 DINO Staveley

Ford Motorcraft 5w20 545 848 298 2005 SM 01/07 SEMI Staveley

Harley Davidson Syn3 20w50 1081 1182 264 1482 SG 11/05 SYN Staveley

Havoline 20w50 425 494 87 1049 SM 03/07 DINO Blackstone

Joe Gibbs Racing XP5 20w50 920 1231 504 SG 04/07 SEMI Blackstone

Kendal GT (Vintage) 20W50 1229 1415 2408 SE 11/05 DINO Blackstone

Kendall GT 20w50 904 1233 2885 SM 06/06 DINO Staveley

Kendall GT 10w30 582 872 278 1416 SM 11/05 SEMI Staveley

Kendall GT 10w40 598 897 282 1565 SM 11/05 SEMI Staveley

Lucas High Perf. Motor Oil 20w50 386 460 214 1079 SM 02/07 SYN Blackstone

Mobil 1 0w40 761 876 167 2630 SM 03/07 SYN Blackstone

Mobil 1 0w40 796 907 178 2650 SM 03/07 SYN Blackstone

Mobil 1 0w40 808 976 185 3256 SL 04/03 SYN Blackstone

Mobil 1 0w40 706 834 148 2246 SM 02/05 SYN Blackstone

Mobil 1 15w50 952 1030 41 2175 SM 03/07 SYN Staveley

Mobil 1 EP 15w50 1193 1376 228 2970 SL 04/07 SYN Blackstone

Mobil 1 EP 15w50 1062 1279 79 2485 SM 04/07 SYN Blackstone

Mobil 1 EP 15w50 906 1024 72 2071 SM 01/06 SYN Blackstone

Mobil 1 EP 15w50 1315 1428 226 2593 SL 11/05 SYN Staveley

Mobil 1 mx4t 10w40 1277 1460 188 2025 SG 03/07 SYN Blackstone

Mobil 1 mx4t 10w40 1411 1623 188 2248 SG 04/07 SYN Blackstone

Mobil 1 R 0w30 1399 1536 178 3051 SG 02/04 SYN Blackstone

Mobil 1 Super Syn 15w50 1343 1390 205 2601 SL 11/05 SYN Staveley

Mobil 1 Truck & SUV 5w40 1034 1247 51 2826 CI-4 04/07 SYN Blackstone

Mobil 1 V Twin 20w50 1329 1949 204 2130 SG 11/05 SYN Staveley

Mobil 5k Clean 10w40 660 1028 2895 SM 06/06 DINO Staveley

Mobil High Mile 10w40 527 1021 2844 SM 06/06 DINO Staveley

Motul 300V Competition 5w40 1317 1409 19 3273 SH 04/05 SYN Blackstone

Motul 300V Competition 15w50 1139 1130 20 2410 SH 05/05 SYN Blackstone

Motul 505.01 VW 5w40 973 1226 2830 SL 05/06 SYN Staveley

Motul Competition 15w50 1148 1327 11 2723 SH 05/06 SYN Staveley

Motul Tekma Mega 15w40 1220 1737 145 3469 CI-4 05/06 DINO Staveley

Mystik 15w40 1130 1224 3104 CI-4 03/07 DINO Staveley

Mystik 10w50 700 799 2003 CI-4 03/07 SEMI Blackstone

Penn Grade 1 Racing 20w50 664 852 2094 SJ 04/07 SEMI Blackstone

Penn Grade 1 Racing 20w50 801 1058 2827 SJ 06/06 SEMI Staveley

Pennzoil 20w50 501 800 223 2062 SM 01/07 DINO Staveley

Quaker State Q Full Syn 5w50 923 908 1917 SM 11/05 SYN Staveley

Redline 15w50 924 1004 27 2287 SM 02/07 SYN Blackstone

Redline 10w40 1440 1872 3039 SL 11/05 SYN Staveley

Rotella 15w40 843 946 26 1881 CJ-4 03/07 DINO Blackstone

Rotella 15w40 996 1130
32
2054 CJ-4 04/07 DINO Staveley

Rotella 15w40 1278 1555 2946 CI-4 11/05 DINO Staveley

Rotella 5w40 1397 1552 2921 CI-4 11/05 SYN Staveley

Royal Purple 20w50 668 763 2034 SJ 02/07 SYN Blackstone

Royal Purple 20w50 1290 1337 3295 SJ 11/05 SYN Staveley

Royal Purple Max Cycle 10w40 4085 1222 2599 SJ 07/05 SYN Blackstone

Royal Purple Max Cycle 20w50 3179 1030 2142 SJ 04/07 SYN Blackstone

Royal Purple Max Cycle 20w50 3907 1458 2478 SJ 11/05 SYN Staveley

Royal Purple Racing 51 20w50 1285 1417 2639 SJ 11/05 SYN Staveley

Royal Purple XPR 10w40 1034 1741 2709 SJ 12/06 SYN Blackstone

Schaeffer 7000 Supreme 20w50 1249 1626 2451 SL 06/06 SEMI Staveley

Schaeffer 9000 Supreme 5w40 1113 1315 10 3126 SL 07/05 SYN Blackstone

Swepco 306 15w40 763 895 92 1732 CI-4 03/07 DINO Blackstone

Swepco 306 15w40 1238 1476 128 2464 CI-4 04/07 DINO Staveley

Torco SR-1 20w50 363 412 759 SG 03/07 SYN Blackstone

Torco SR-5 20w50 1072 830 10 1481 SG 02/07 SYN Blackstone

Torco T-4SR 20w50 1059 969 1293 SG 05/06 SYN Staveley

Torco TR-1 20w50 670 571 958 SG 03/07 SYN Blackstone

Torco V Series ST 20w50 1030 1286 2231 SG 05/06 SEMI Staveley

Valvoline All Fleet Plus 15w40 1110 1232 3559 CI-4 10/06 DINO Staveley

Valvoline Durablend 20w50 566 732 13 2606 SM 06/06 SEMI Staveley

Valvoline Max Life 20w50 691 879 17 2170 SM 11/05 DINO Staveley

Valvoline Prem. Blue 15w40 1314 1838 158 4329 CI-4 06/06 DINO Staveley

Valvoline Synpower 20w50 605 689 1786 SM 03/07 SYN Blackstone

Valvoline VR1 20w50 1085 1293 17 2242 SL 11/05 DINO Staveley

Valvoline VR-1 NSL 20w50 835 976 10 819 SL 03/07 DINO Blackstone

Valvoline VR-1 NSL 20w50 842 962 11 838 SL 03/07 SYN Blackstone

Bardahl No Leak/Smoke 53 4 0 11/05 O/A Staveley

Boron Motor Silk 116 0 05/06 O/A Staveley

CD-2 Maxx Detergent 1 7 2416 11/05 O/A Staveley

CMW Racing Concentrate 2292 1147 358 06/06 O/A Staveley

GM Cam Lifter Prelube 5710 5876 29004 01/07 O/A Blackstone

GM EOS Assembly Lube 5762 6221 8265 01/07 O/A Blackstone

Lucas Oil Stabilizer 36 13 0 01/07 O/A Staveley

Power Service Oil Extender 3567 4945 6394 11/05 O/A Staveley

Schaeffer Micron Moly 110 5 0 08/06 O/A Staveley

STP Blue 1704 2436 88 11/05 O/A Staveley

STP Red 2115 3932 901 11/05 O/A Staveley

Valvoline Max Life Protect 537 768 22 3871 11/05 O/A Staveley

Valvoline Synpower 356 551 650 11/05 O/A Staveley
yes, the dates are old on most of this, but you can see who was and probably still is using high zddp

here is mobils level. there is a chart to click on at the end of the question
http://www.mobiloil.com/usa-english/m ... obil/Zinc_Motor_Oils.aspx

after reading the Mobil 1 FAQ for high mileage engines, 10-40 sounds like the perfect fix.

Quote:

I actually looked at my gauge today.
@ 210 Oil Temp,
Idle 20-22
Above 2k - 45
Below 2k (lug in 6th) 38-40

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That's one of the reasons all the brew-ha-ha on oil makeup isn't even on my radar screen.
I ran a SBC on Quaker State dyno to 200k before ir started using a half qt. in 4,000 mi and ran the motor to 250k

My Vortec is at 140k using M1 with zero oil usage.
My LT1 is at 90k with zero.

I figure by the time the extra shit in the wonder oils starts paying off, it's time to build the motor anyway.

I am not talking wonder oils... just a bit more viscosity to be sure pressure is kept up.

At warm idle, mine is down around 10 PSI... sometimes lower when the AC kicks in.

So something is out of whack... could be the sensor, I have another one, I will swap it out.

Quote:

Yea check the sensor.

But, you can idle for a week on 10 psi.

I was in Mobil's dyno facility. I happened to see a motor (Olds small block) that was idling at 5 psi, The manager there said that it could idle there all day with no effect on any of the parts.

I worry about that low a pressure reaching the valve train ok.

I know it's supposed to be ok.. but it strikes me as really low.

Quote:

Your concern is understandable.
The valvetrain doesn't require very much, not really pressure just a bit of flow.

And if your sensor checks out, maybe the 10-40 will help.

I have a 12 psi warning light on the racecar, it's always on at the end of a race @ idle and a bit above. Never had a problem bit the motor does get rebuilt often.

you could always drop the pan, take the oil pump out and put a higher volume/pressure pump in there. Or change the spring.
Or, 383....

Steve - I do like the way you think... 383 is on my list...

But... I want to get a few things done first. So it's a low priority right now.

I will swap oil sensors and see what that does. I also have a mechanical gauge I can set in there and see what it says.

I did swap sensors, and the oil pressure has perked up on the gauge.

I need to do the mechanical gauge test... but it appears that either my old sensor read low, or the new one reads high... flip a coin! However, the new one is back up to where my pre replacement was.