Users of 15w40 or 20w50, check in please...

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Dec 6, 2003
Stockbridge, GA
Where do live, what do you drive, how many miles on the vehicle, do you use it year round, and WHY?

I live in Atlanta, GA and own a 1993 Plymouth Acclaim with 178k and a 1990 Nissan pickup with 131k and am contemplating using one of these year-round.
I have use the 20w-50 for about 5 years here in Eastern North Carolina. My toyota starting using oil about 150,000 and I switched from 10w-40 to Castrol gtx 20w-50. I have an additional 100,000 and it has protected the car well through two overheats where the radiator went and then a hose. Radiator shop said the headgasket was blown but I just put in a new Radiator myself and all is well. That was about 2 years ago.
I have used it in my TR3 for 30 years. The original engine went 100,000 and the rings went.
Rebuilt in 1990 and has gone an additional 28,000 with no problems so far.
I think it is an excellent oil for high milage
cars that surely have large clearences. It is recomended by Triumph in the owners manual.

[ March 01, 2004, 08:52 PM: Message edited by: TR3-2001SE ]
Used 20w-50 Valvoline VR1 last year.

Using 15w-40 Mobil Delco 1300 Super this year.

85 Nissan 300zx (VG30e) used as a autocross race car that sees about 25 events over the summer.
I use Rotella T 15W40 in my '65 Chevy truck. It has a new 307/283 stroker I built for it that has be in the truck for about a year. I live one mile form work and the stores so it does not see a lot of miles yet. The motor was built to run at sustained 3000 to 3500 RPM but once I got it built everything had changed. I change the oil every six months if it needs it or not which works out to be about every 600 miles or so.
I'm useing Delo 15W-40 in my 1969 solid lifter BBC Chevelle and in my 1979 Olds Culass Supreme 305 Chevy 4 bbl engine.Northern Calif East Bay climate where it rarely gets even into the 30's F.
We use Pennzoil HD Longlife 15W-40 year round in my brother's '85 Accord. It's got 240,000 miles on it, and started buring a lot of oil about 10,000 miles ago. It rarely goes below 20F here, and the 15W-40 brought oil consumption down. It's been cleaning the engine out (slowly but surely) too, this is great oil!
Pennzoil LongLife 15W-40 in the wife's '91 420SEL since our purchase 3 years ago & soon w/b using Delo 400 15W-40 in the '73 450SE... Once PHASE II of the Auto-Rx treatment is done.
This winter I used a 5W40 in -18 degree weather!

I normaly use M1 15W50 in the warm months and 10W30 in the winter months. In used vechiles that I own that I do not push hard I frequently use 15W40 or 20W50 inthe warm months and 10W30 int he winter.

I currently live in Michigan but have lived in many countrys and many states. If the temp stays above daily high of 30-40F I have been known to run 15W50 M1 year round.

I have run this in Imports and Domestics with and without lifters!
I use Mobil Delvac 15w-40 during the warmer months in both my '97 Mercury Villager and '02 Chevy Suburban. I have been using Shell Rotella 5w-40 during the winter months, but am thinking about switching to Chevron Delo 10w-30 next year. The Delo 10w-30 has fantastic cold pumping numbers and it much cheaper than the Rotella synthetic. Why do I use HDEO's in gasoline engines you ask? I've been running HDEO's for 20 years in everything I own. The engines just run forever, and are absolutely spotless inside - even after a 250,000 miles. Clean engines last.

I've been using 20W-50, 20W-50 plus STP, 25W-50, 25w-60, and 25W-70 for 18 years.

It's only in the last 4 years that I've "discovered" XW-40, (except my BJ42 that had Delvac 1330 in it).

I reckon the 5 to 15W-40s HDEOs are a very useful oil, and doubt that I'll change my mind in a hurry.
Palut, do you think if you had been using the the 15-40 a lot earlier that the Accord would never have seen the consumption issues nor dirty engine?

And John, the 5-40 should have been thinner at -18F than the 10-30 that you said you were previously using in winter.

Until recently, the local BMW dealer offered a choice between either the BMW synth. 5-30 or BMW conven. 15-40. So they must somehow be comparable in order to get this manuf.'s approval....and I believe it was the 'golden standard' conv. fill in Europe until recently as well.
In MA, I used 15W-40 year round in a 1990 BMW 325i with 140k, now I just use it in the summer. Car is stored winter. I'm going to switch my 92 Corolla with 180k on it to 15W-40 on the next change as well. Car gets driven daily in winter and on rainy days through summer.
15W-40 Chevron Delo 400 since 1998 in:

1992 BMW 325i 123,000 mi
1994 Ford F-150 5.0l 125,000 mi

15W-40 Shell Rotella T is currently in:

1972 Buick 350ci 65,000mi
1987 Dodge Van 5.2l 80,000mi

Pennzoil Longlife previously used since the 1980's in:

1968 VW new engine
1957 Chevrolet 283ci mileage unknown

Except for the Ford, these cars never see temperatures below +40F in coastal Southern California. The Ford is operated in the mountains and desert with temperature extremes of about +10F to +100F. The same oil is used all year.

The Buick, Chevrolet and VW are collector cars in runnable storage. The others are on an annual oil change schedule, as annual mileage is relatively low. I like the more robust base oils and additive packages of HDMO, especially the high TBN for stored or infrequently driven ones due to the extra corrosion protection.

[ March 02, 2004, 12:03 PM: Message edited by: Jimbo ]
Use Vavoline 20W-50 VR1 in my 3.0 Mercruiser engine. Definently keeps the oil pressure up at WOT and idle. No leaks yet, it's a '96.
Originally posted by Dr. T:
[QB] Palut, do you think if you had been using the the 15-40 a lot earlier that the Accord would never have seen the consumption issues nor dirty engine?

Actually, I believe most of the problem came from when I was at college in southeast Idaho. I knew absolutely nothing about oil! It would get as low as 20 or 30 below 0, I had 15-40 in it, and wouldn't let it warm up at all. I think it started burning a little oil after that. Then my brother let the oil level fall off the dipstick for a few thousand miles. I screwed up bad, and he screwed up worse!
Think about this folks:
With my old VW Passat GLX the summer fill (per manual) was 20w-50 and the winter fill 15w-40...

Think about this folks:
With my old VW Passat GLX the summer fill (per manual) was 20w-50 and the winter fill 15w-40...

Years ago when I was young a stupid, I had a 68 427 Corvette. I used straight 50W Valvoline racing year around. It never gets much below freezing here, but it did crank hard in the winter, I put 100,000 really hard miles on that car before I sold it and it never used much oil! It was fast, but would have been even faster if I would have known to use a thinner oil! Hey, I thought I had a race car!!

Palut, do you think if you had been using the the 15-40 a lot earlier that the Accord would never have seen the consumption issues nor dirty engine?

I'd like to see a car that has 200K + miles ran on a 50wt oil all it's life put on a 5w-20 to see if it consumes oil.

Years ago running a thicker oil was probably ideal, when the oils were of less quality. But when you take a good synthetic, you want the oil with the best wear for your particular engine and the least amount of drag. If I can run a good 30wt and get the same wear and more HP, I'm running that over a 50wt oil any day.
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