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#4782892 - 06/10/18 09:30 AM Looking at 75w90's
buck91 Offline

Registered: 04/17/12
Posts: 2501
Loc: West Michigan
Going to work on doing my 100k service on the F150 this summer and one of the jobs is the front dif. I'm sure its in just as bad of need as the transfer case was. Spec is 80w90, I think I'll go with the 75w90 synthetic alternative but I'm a little torn on which one to get. Motorcraft and Amsoil run about the same price but I can save some money going with SynPower or M1 which are also about the same price as eachother and a couple bucks less per quart than Amsoil.

In the past I've had no troubles with Synpower. I did have some wheel bearing issues on my Mustang after switching to M1 which I cannot rightly explain as levels were fine and mileage wasn't too excessive at that time. Is there any real difference between the two? I have to imagine both are using grp III+ these days, and both seem highly reputed. Truck seems most 4WD action in the cold of winter so I do think the 75w will be a slight advantage.

Addendum: Looks like M1 is very slightly less impressive on paper.
VI: 150
PP: -48C
Vis 100C: 15.6
Vis 40C: 100

VI: 146
PP: -39C
Vis 100C: 14.6
Vis 40C: 103

I know numbers are FAR from the whole story but it seems the SynPower is marginally superior?

Edited by buck91 (06/10/18 09:38 AM)
2011 F150 4x4 5.0L
1996 Mustang GT 5spd/ragtop

#4782900 - 06/10/18 09:40 AM Re: Looking at 75w90's [Re: buck91]
demarpaint Offline

Registered: 07/03/05
Posts: 30150
Loc: NY
I went with Mobil 1. Pep Boys has coupons from time to time offering 25% off and I loaded up on it then. Both my Jeeps have it in them, and I've used it in several other vehicles over the years. I never had a problem with it.
God Bless Our Troops

#4782911 - 06/10/18 09:51 AM Re: Looking at 75w90's [Re: buck91]
zeng Offline

Registered: 09/01/15
Posts: 2214
Loc: Malaysia
Kindly consider High KV40C 75W90 in Schaeffer 293 or jewels in States in Lucas 75W90.

#4782929 - 06/10/18 10:10 AM Re: Looking at 75w90's [Re: buck91]
CleverUserName Offline

Registered: 11/08/17
Posts: 208
Loc: California
Delvac synthetic 75w90 is GL5 and affordable in gallon jugs.

#4782940 - 06/10/18 10:28 AM Re: Looking at 75w90's [Re: buck91]
ZZman Offline

Registered: 03/17/08
Posts: 5903
Loc: Michigan
I have read tests that showed Amsoil #1 and Mobil #2
2003 Mercury Grand Marquis. Rotella T6 Multi-Vehicle oil
2008 Sebring Hardtop convertible. Rotella T6 Multi-Vehicle oil
2006 Kawasaki Vulcan 900 LT. Amsoil Metric 10w-40

#4782949 - 06/10/18 10:39 AM Re: Looking at 75w90's [Re: buck91]
aquariuscsm Offline

Registered: 12/30/06
Posts: 18439
Loc: Dallas,Tx USA
Look at the gear oil uoas.

Amsoil Severe Gear all the way!! That's all I'll ever use.
1996 Nissan 300ZX 5-speed,Arctic Pearl(#175 of 300)
Quaker State Ultimate Durability 10W30
2012 Honda Accord Coupe EX-L 2.4,auto,San Marino Red
Quaker State Ultimate Durability 5W30

#4782961 - 06/10/18 10:51 AM Re: Looking at 75w90's [Re: buck91]
IndyFan Offline

Registered: 06/16/05
Posts: 609
Loc: Danville, Indiana
I've been running Supertech Synthetic 75w90 in the front diff of my 08 Wrangler, and 85w140 in the rear. It seems to be serving well with no issues. I do some towing with that Jeep, too.
18 Jeep JLUR Wrangler 3.6 5k
15 Ford Transit 93k, Reman 3.5 @85k
08 Jeep Wrangler 3.8 123k
01 Ford F150 Crew 5.4 79k
99 Mercedes E430 Sport 89k

#4782984 - 06/10/18 11:42 AM Re: Looking at 75w90's [Re: buck91]
barkingspider Offline

Registered: 12/22/13
Posts: 2077
Loc: socal
Any name brand 75w90 (or 80w90) will do fine. Of the 2 u mentioned, I like Val Syn better than M1
06 Cadillac Escalade Ext
17 Cadillac ATS (wife)
05 Toyota Camry (daughter)
11 GMC Canyon off-road (daily)

#4782989 - 06/10/18 11:48 AM Re: Looking at 75w90's [Re: CleverUserName]
4WD Offline

Registered: 09/21/10
Posts: 6884
Loc: Texas
Originally Posted By: CleverUserName
Delvac synthetic 75w90 is GL5 and affordable in gallon jugs.

Itís now Delvac 1 Ö have had that in G80 for 2-1/2 years now Ö

#4783005 - 06/10/18 12:00 PM Re: Looking at 75w90's [Re: buck91]
Patrick0525 Offline

Registered: 07/23/14
Posts: 216
Loc: PA
@4WD Delvac doesnít have friction modifier. Did you add it to the gear oil? And how much?
'14 Toyota Venza 3.5L 70K mi
TGMO 0W-20/Toyota filter (winter)
PP 0W-20/Fram Ultra filter(spring/summer)

#4783047 - 06/10/18 01:03 PM Re: Looking at 75w90's [Re: buck91]
CT8 Offline

Registered: 10/09/14
Posts: 11483
Loc: Idaho
I have been running syn 75W-140 in everything.
"Don't let your preconceived notions get in the way of facts."
Geoff Metcalf

#4783089 - 06/10/18 01:51 PM Re: Looking at 75w90's [Re: buck91]
Pajero Offline

Registered: 05/05/12
Posts: 953
Loc: Rio Rancho, NM
Amsoil Severe Gear oil!


Always remember "Planned obsolescence."

1994 Montero SR 3.5 DOHC, 133,xxx
Fram Ultra/ Snorkel with Pre-filter

#4783135 - 06/10/18 03:12 PM Re: Looking at 75w90's [Re: buck91]
donnyj08 Offline

Registered: 08/12/12
Posts: 3039
Loc: Cincinnati
Valvoline or Castrol 75w90 Syntheic. Both under $10 a jug and usually available at autoparts stores.
2008 Silverado Z71 LT 90k Maxlife FS 5w30
2010 Ford Escape 167k QSUD 5w20
2016 Yamaha XSR900 12k, Rotella 15w40 Yamaha Filter.

#4783284 - 06/10/18 06:48 PM Re: Looking at 75w90's [Re: buck91]
SubieRubyRoo Offline

Registered: 05/14/12
Posts: 1255
Loc: Winchester, Indiana
Motul Gear 300

#4784098 - 06/11/18 05:10 PM Re: Looking at 75w90's [Re: Patrick0525]
CleverUserName Offline

Registered: 11/08/17
Posts: 208
Loc: California
Originally Posted By: Patrick0525
@4WD Delvac doesnít have friction modifier. Did you add it to the gear oil? And how much?

Iím also running D1 75w90 in a G80. This type of LS diff. doesnt require any friction modifiers.