Selecting Engine Oil Wt vs Outside Temps
Selecting Engine Oil Wt vs Outside Temps
(OP)
Checked thread 89-62555, but I don't think it quite answered my question. If it did, just give me the ref, and accept my apologies.
I’m just a shade-tree mechanic- after oil & filter changes, maybe a battery or thermostat, today’s auto maintenance is beyond me. About 15 years ago, I encountered a very unique Texaco Customer Hotline: 1- They actually answered the phone, and 2- I spoke with an engineer!! (Alas, 6 months later, the line was answered by a ‘customer rep’ who either knew, or would commit to – nothing.) btw- I checked thread 89-62555, but I don't think it quite answered my question. If it did, just give me the ref, and accept my apologies.
On that lucky occasion I spoke with the engineer, he sheepishly admitted (“I’m probably not suppose to say this”) that auto manufacturers were recommending the thinnest possible oils, to get better mileage, but with minimum consideration to engine life. As I keep my cars for about 100,000 or more miles, I’d like to know if he was right. In the warmer temps of South Florida, I always insisted on 10-40, rather than the 5-30 dealers tried to sell. Now I live in Arizona. I might go 5-30 for a winter start in Flagstaff, but when I have to drive in Phoenix in August, I'd like to know if the engineer's admission is still valid. Seems to me, the ideal oil would be 5-60!
Thanks in advance, sorry to be so wordy. Rich
Comments?
I’m just a shade-tree mechanic- after oil & filter changes, maybe a battery or thermostat, today’s auto maintenance is beyond me. About 15 years ago, I encountered a very unique Texaco Customer Hotline: 1- They actually answered the phone, and 2- I spoke with an engineer!! (Alas, 6 months later, the line was answered by a ‘customer rep’ who either knew, or would commit to – nothing.) btw- I checked thread 89-62555, but I don't think it quite answered my question. If it did, just give me the ref, and accept my apologies.
On that lucky occasion I spoke with the engineer, he sheepishly admitted (“I’m probably not suppose to say this”) that auto manufacturers were recommending the thinnest possible oils, to get better mileage, but with minimum consideration to engine life. As I keep my cars for about 100,000 or more miles, I’d like to know if he was right. In the warmer temps of South Florida, I always insisted on 10-40, rather than the 5-30 dealers tried to sell. Now I live in Arizona. I might go 5-30 for a winter start in Flagstaff, but when I have to drive in Phoenix in August, I'd like to know if the engineer's admission is still valid. Seems to me, the ideal oil would be 5-60!
Thanks in advance, sorry to be so wordy. Rich
Comments?





RE: Selecting Engine Oil Wt vs Outside Temps
thread71-99132 may help.
RE: Selecting Engine Oil Wt vs Outside Temps
RE: Selecting Engine Oil Wt vs Outside Temps
<<< Unless you designed the engine and/or the oil, I recommend you stick to the manufacturer's recommended grades with a quality name brand oil. >>>
Just to be clear- you believe I should stay with manufacturer’s 5-30 recommendation, in slow traffic, with OATs above 110F ?
I keep (cynically :) wondering if passenger auto manufactures, pressed with higher MPG requirements, might be ‘recommending’ more toward mileage, than getting the engine well beyond 100,000 miles.
Thanks again,
Rich
RE: Selecting Engine Oil Wt vs Outside Temps
RE: Selecting Engine Oil Wt vs Outside Temps
Rich
RE: Selecting Engine Oil Wt vs Outside Temps
Oh, yeah. I forgot to mention, the car is just over 146,000 miles and still gets it's usual 21/22 mpg and uses no oil between changes...still on the OEM sparkplugs...just passed it's first California smog test...What more can I say?
PS: I don't use these 'light weights' on most of my vintage cars...either 15W-50 Mobil 1 or 20W-50 Castrol in the older cars and my diesel. After all, we are in Socal where it never (usually) gets colder than 40f !
Rod
RE: Selecting Engine Oil Wt vs Outside Temps
If the 5w20 did so well for the newer car, why the heavier wts for the viintage ones?
Rich
RE: Selecting Engine Oil Wt vs Outside Temps
Rod
RE: Selecting Engine Oil Wt vs Outside Temps
Not trying to plug the forum, but I''ve asked my initial thread question to numerous mechaniics & service managers, for 10+ years. The answer was always a shrug and ''that's what the manual says'
This has really helped- both in testimonials & explanations.
Thanks again, guys.
Rich
RE: Selecting Engine Oil Wt vs Outside Temps