Do you oilers know of any owner's manual for any automobile or light pickup that recommends use of 10W40? I do not and wonder why guys on here and other threads talk about using it. Some manuals even specifically state that it should not be used.
10W40
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My 2005 Hyundai Elantra manual says pretty much anything from 5W30 to 20W50 is ok, depending on your climate of course. Here in Georgia, I'll probably use the 10W40 all year, if I use dino. For synthetic, I'd probably go with a 5W40 Castrol or Valvoline, or maybe Mobil 1.
I am still waffling between using dino with LC, or a synthetic, w/wo LC. OCI will be 5K/6mo regardless, so I'm not interested in stretching the OCI past what's recommended in the manual. Gotta keep that 100K/10yr warranty in effect.
My 93 M-B 190 has 10-40 in the owners manual. Along with 20-50. According to my owners manual 5-30 is only to be used at temps under 14 degs F. Right now I have straight 30wt. in it with 5oz's of Valvoline oil treatment....doing just fine.
The Kia Sedona (minivan) utilizes the Hyundai 3.5L 6 cyl. engine, and Kia recommends a 10W-40, or 10W-50, for temperatures above about 86'F. Of course, some motorcycles require a 10W-40. IMHO I find it strange that a VI-I ladened syn 5W-40 is cutting edge...uh, excuse me "Euro," and a syn 10W-40 is obsolete.
My '95 F150 4.9L manual says to use 10w30. I would but I get better oil pressure with 10w40. I don't think the engine really changed from the earlier years where the manual allowed nearly any grade from 5w30 up depending on the ambient temperatures.
Ditto for 10w40(Chevron Supreme) in my project 190E, but now running Delo 400 15w40 for summer..noticed engine is quieter with way better oil psi.
fish,
We sometimes reccomend 10W40 because lab research shows acceptable wear levels for almost all engines at 10W40,15W40 or 20W50 viscosity in above-freezing air temperature operation.
In fact, 10W40 through 20W50 grade oils frequently turn in BETTER wear levels than do 5W20, 5W30 or 10W30 oils in most engines.
The engines where you want to be careful about deviating from a 5W20 or 5W30 reccomendation include Ford's modular 4.6 liter V8, Ford's 3.0 liter Duratec V6, Mazda's current rotary of RX8 fame, and any Honda with VTEC.
And on a semi-related note, always run diesel-rated oils in diesel engines, usually 15W40 or synthetic 5W40 grade, sometimes SAE 30HD.
We sometimes reccomend 10W40 because lab research shows acceptable wear levels for almost all engines at 10W40,15W40 or 20W50 viscosity in above-freezing air temperature operation.
In fact, 10W40 through 20W50 grade oils frequently turn in BETTER wear levels than do 5W20, 5W30 or 10W30 oils in most engines.
The engines where you want to be careful about deviating from a 5W20 or 5W30 reccomendation include Ford's modular 4.6 liter V8, Ford's 3.0 liter Duratec V6, Mazda's current rotary of RX8 fame, and any Honda with VTEC.
And on a semi-related note, always run diesel-rated oils in diesel engines, usually 15W40 or synthetic 5W40 grade, sometimes SAE 30HD.
The GS series of Suzuki motorcycles were spec'ed for 10/40 oil. 77-86.
I would think 10w30 would be a fine grade for these.
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The manual on my 02 Nissan Sentra allows the use of 10W-40 or a 10w30 at temperatures above 0F.
UOA's here have typically shown that 10W40 protects very well. I've got a friend with a 6 cyl Ford Ranger, '89 model. It's got just under 335,000 miles on it now, without every having been torn down. Valvoline 10W40 standard stuff to about 100K, then it's been 10W40 Valvoline high mileage Maxlife ever since.
I think the 10W40's do their magic by shearing to a heavy 30 somewhat early on, but they hold that 30 weight viscosity for a few thousand miles.
Whether that theory is right or not, there is something about the oft maligned 10W40's ability to really protect an engine. Again--check UOA's here and elsewhere...
Dan
I think the 10W40's do their magic by shearing to a heavy 30 somewhat early on, but they hold that 30 weight viscosity for a few thousand miles.
Whether that theory is right or not, there is something about the oft maligned 10W40's ability to really protect an engine. Again--check UOA's here and elsewhere...
Dan
fish
My '98 WRX manual called for a 10w30 or 10W-40 SH rated oil, amd simillarly my '00 WRX owners manual called for a 10w30 or 10W-40 SJ rated oil.
SH rated 10W-40 oil? if you beleive some of the hype on this board then none of the '98 model WRX's should have made it to the new millenium without very rounded cam lobes & very dead turbos running 7500 mile OCI's.
My '98 WRX manual called for a 10w30 or 10W-40 SH rated oil, amd simillarly my '00 WRX owners manual called for a 10w30 or 10W-40 SJ rated oil.
SH rated 10W-40 oil? if you beleive some of the hype on this board then none of the '98 model WRX's should have made it to the new millenium without very rounded cam lobes & very dead turbos running 7500 mile OCI's.
2000wrx, I'm curious. Do your WRXs have water cooled turbo(s) and/or an oil cooler?
Acceptable for use in a 2005 Subaru Impreza WRX STi as well:
427Z06: Not sure about the WRX, but the WRX STi has both a water-cooled turbo and an oil cooler in the form of an oil-to-coolant exchanger.
427Z06: Not sure about the WRX, but the WRX STi has both a water-cooled turbo and an oil cooler in the form of an oil-to-coolant exchanger.
427Z06
Yes my WRX does have it's turbo water cooled, and there is an attempt at an oil cooler whereby the oil filter is mounted on a heat exchanger that has engine coolant running through it. I have heard the effectiveness of this unit is somewhat below a dedicated, finned, oil to air radiator.
The japanese have been water cooling most of the turbos that I know of for long time; late 80's at least in some cases.
Yes my WRX does have it's turbo water cooled, and there is an attempt at an oil cooler whereby the oil filter is mounted on a heat exchanger that has engine coolant running through it. I have heard the effectiveness of this unit is somewhat below a dedicated, finned, oil to air radiator.
The japanese have been water cooling most of the turbos that I know of for long time; late 80's at least in some cases.
The owner's manual for my '83 F250 indicates that 10W-40 is acceptable in hot weather, but also says that xW-30 is preferable.
I remember the bad old days (mid 1970s), when Ford and GM warned everyone to avoid any 10W-40 motor oil. In my weather wimp climate (coastal southern California) and with my oil cooking engine (VW/Audi 1.8T), a good synthetic 10W-40 oil might make alot of sense.
AndyH's owners manual page is really interesting. I think it could apply to all engines if the manufacturers cared to make an effort to write it in their owners manuals.
It appears 5w30 is recommended for all applications because the thicker oils "may be used" in heavy duty applications.
In Connecticut I wouldn't use 10w40 in Dec, Jan or Feb. I would use 5w30.
It appears 5w30 is recommended for all applications because the thicker oils "may be used" in heavy duty applications.
In Connecticut I wouldn't use 10w40 in Dec, Jan or Feb. I would use 5w30.
I use 10w40 in metro Detroit. It generally does not get much below zero F near the city. I also "cheat" with an oil pan heater when parked at home, but I park outdoors. If I were parked in the garage, probably could do without the oil pan heater.
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