As some of you guys know I live in a hot tropical country near the equator, called Malaysia. The weather I would say is very similar to Miami. On hot afternoons, 40 C is possible.
In Malaysia, oil availability is severely limited. Any oil that is 0WXX or 5WXX is a synthetic or synthetic blend. The most common dino available is 20W50, and then 10W30, which are an older API spec. We have plenty of choices for 5W40 group3 synths here, and and I just have to wait for them to be on sale from time to time, usually Shell Helix Ultra 5W40, Castrol Edge 5w40 and Mobil 1 5W50.
In general people here never use 30wt oils for their sub compacts or bigger , for instance Toyota vios ,altis or camry. The mechanics here always spec 40wts as minimum, citing the high temperature. Believe it or not manuals here still reflect that "choosing oils by ambient temperature" guideline. There seems to be an irrational fear over here of 30wt oils. I too used to fall in that group, until I joined BITOG.
I drive a 1980s Proton Saga, which is a copy of the 1980s Mitsubishi /Dodge colt. Recently I just got both oil temp and pressure gauges and have been monitoring the readings I get these last few days. Current fill is Shell Helix ultra API SN 5W40, before the pureplus version. I have now two 4L bottles of the pureplus version I bought on sale, for my future oil changes.
My oil pressure at "cold" start (26C) is 90psi. It would then drop as the temperature rises, at 72C the oil pressure is at 30psi. At 90C,idle, 20psi.it seems to stabilize at 93C at low loads,about 2500rpm in 5th gear,speed of 82kmh. the psi at this rpm and load is 60psi.
If I gas it to 3000rpm to 3200rpm, which gives me 100 to 110kmh, the pressure rises to 70psi, and the temp rises to 98C and the psi dropped to 66, since the temp increase and the viscosity decreased. I have not got the chance to test how far will the temp rise at this rpm because I ran out of road to my workplace.
I noticed that the oil temp reached its equilibrium, where its not rising or going down, at 2500rpm in 5th gear.
I have done quite a lot of reading on bitog and elsewhere, about intra fluid friction. My question is, is the 40wt too thick for my engine, causing intra fluid friction at the bearings, and increasing the heat at the bearings? If so, will going to a 30wt help to raise this equilibrium point to perhaps..4000rpm.
My Purpose is to delay this increase in heat of the oil to a higher rpm, and thereby reducing my bearing wear. The last UOA I did showed 25ppm of iron and 23ppm of lead on AMSOIL 10W40 in a 15000km run.
Is 70psi at 3000rpm too high a pressure ?
Looking at my readings, it should be possible to go for a 30wt oil, probably a 5W30.
there are only a few choices available here.
1. Shell HX7 5W30 semi syn, cst of 11.93 at 100C
2. Pennzoil Ultra 5W30, syn, cst of 10.3 at 100C
3. Eneos sustina 5W30 syn cst of 10.9 at 100C
4. Eneos ecotouring 5W30, semi syn not sure the cst
Shell Helix Ultra 5w40 cst at 100C is 13.1
The semi syns are much cheaper than the full syns. However I am a bit reluctant to go for the HX7 as the cst is almost that of a low 40wt. Should I go for a low 30wt oil so that I can get lower oil temps. The logic is if the oil temp doesn't rise at 3000rpm, say it stays at 94 to 95C, the cst of the 30wt oil will not reach its 100C rating, but will be pretty close.
Another option is to buy a low 30wt like PU, get 3qts, then mix the rest 660ml of Shell Helix 5W40. If I go the mixing option, do I premix before or after pouring in the crankcase?
With a 30wt I might be getting 50 psi at 3000 rpm, and 60psi at 4000rpm. Does this sound like a more reasonable oil pressure ..considering most cars bypass relieves open at 65 to 75psi ?
I would love to hear your thoughts and experiences. If this pans out, I will keep using 30wts as long as I possibly can.
In Malaysia, oil availability is severely limited. Any oil that is 0WXX or 5WXX is a synthetic or synthetic blend. The most common dino available is 20W50, and then 10W30, which are an older API spec. We have plenty of choices for 5W40 group3 synths here, and and I just have to wait for them to be on sale from time to time, usually Shell Helix Ultra 5W40, Castrol Edge 5w40 and Mobil 1 5W50.
In general people here never use 30wt oils for their sub compacts or bigger , for instance Toyota vios ,altis or camry. The mechanics here always spec 40wts as minimum, citing the high temperature. Believe it or not manuals here still reflect that "choosing oils by ambient temperature" guideline. There seems to be an irrational fear over here of 30wt oils. I too used to fall in that group, until I joined BITOG.
I drive a 1980s Proton Saga, which is a copy of the 1980s Mitsubishi /Dodge colt. Recently I just got both oil temp and pressure gauges and have been monitoring the readings I get these last few days. Current fill is Shell Helix ultra API SN 5W40, before the pureplus version. I have now two 4L bottles of the pureplus version I bought on sale, for my future oil changes.
My oil pressure at "cold" start (26C) is 90psi. It would then drop as the temperature rises, at 72C the oil pressure is at 30psi. At 90C,idle, 20psi.it seems to stabilize at 93C at low loads,about 2500rpm in 5th gear,speed of 82kmh. the psi at this rpm and load is 60psi.
If I gas it to 3000rpm to 3200rpm, which gives me 100 to 110kmh, the pressure rises to 70psi, and the temp rises to 98C and the psi dropped to 66, since the temp increase and the viscosity decreased. I have not got the chance to test how far will the temp rise at this rpm because I ran out of road to my workplace.
I noticed that the oil temp reached its equilibrium, where its not rising or going down, at 2500rpm in 5th gear.
I have done quite a lot of reading on bitog and elsewhere, about intra fluid friction. My question is, is the 40wt too thick for my engine, causing intra fluid friction at the bearings, and increasing the heat at the bearings? If so, will going to a 30wt help to raise this equilibrium point to perhaps..4000rpm.
My Purpose is to delay this increase in heat of the oil to a higher rpm, and thereby reducing my bearing wear. The last UOA I did showed 25ppm of iron and 23ppm of lead on AMSOIL 10W40 in a 15000km run.
Is 70psi at 3000rpm too high a pressure ?
Looking at my readings, it should be possible to go for a 30wt oil, probably a 5W30.
there are only a few choices available here.
1. Shell HX7 5W30 semi syn, cst of 11.93 at 100C
2. Pennzoil Ultra 5W30, syn, cst of 10.3 at 100C
3. Eneos sustina 5W30 syn cst of 10.9 at 100C
4. Eneos ecotouring 5W30, semi syn not sure the cst
Shell Helix Ultra 5w40 cst at 100C is 13.1
The semi syns are much cheaper than the full syns. However I am a bit reluctant to go for the HX7 as the cst is almost that of a low 40wt. Should I go for a low 30wt oil so that I can get lower oil temps. The logic is if the oil temp doesn't rise at 3000rpm, say it stays at 94 to 95C, the cst of the 30wt oil will not reach its 100C rating, but will be pretty close.
Another option is to buy a low 30wt like PU, get 3qts, then mix the rest 660ml of Shell Helix 5W40. If I go the mixing option, do I premix before or after pouring in the crankcase?
With a 30wt I might be getting 50 psi at 3000 rpm, and 60psi at 4000rpm. Does this sound like a more reasonable oil pressure ..considering most cars bypass relieves open at 65 to 75psi ?
I would love to hear your thoughts and experiences. If this pans out, I will keep using 30wts as long as I possibly can.
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