Hey guys, with the summer just around the corner and an anticipated hot one, I just don't feel comfortable with 10w 30 in my 03 Bonneville SLE and my mom's Sable w/3.0 DOHC.Synthetics is not an option, so what do you guys think. I'm sure there are people out there that use 20w 50 without any issues, right?
Anybody use 20w 50 for the summer?
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There are probably many here that say you won't need a 20W50 or even a 10W40, but I've always liked a thicker oil in the summer. I've been using Delo SAE30 in my Jeep and like to use 10W40 and Delo 15W40 too. I've used 20W50 before as well, and have never had any issues.
10w30 should be perfectly fine, 20w50 might be overkill. If you're THAT worried, a 15w40 like Delo or Rotella should get you through the summer just fine, but they are by no means necessary. Maybe even a 10w-40 for peace of mind?
During hot weather operation, Volvo spec'd 15W-40 for the red block motor in the 240/740/940 family (of which I own or maintain six). I used to use 20W-50 in these engines in the summer, but have lately been using Delo 15W-40 or Shell Rotella 15W-40 in the N/A motors and Rotella T syn 5W-40 in the turbos, although two of the turbos will run GC this year.
Unless you have consumption issues, I'd think a 15W-40 would be more than adequate if you really want to go thick.
Unless you have consumption issues, I'd think a 15W-40 would be more than adequate if you really want to go thick.
Wholeheartedly agree. I live in TX and there's no need for a 20w-50 in a car spec'd for a 30 wt. You say synthetics are not an option? Don't you think a syn would hold up BETTER in the heat?
I take my Ferrari F355B racing in the 103dF heat of Texas summers. Since my race car has an oil temperature guage, I have used this to determine that the car prefers a thin 5W-40 oil over the 15W-50 and 20W-50 oils I tried (all top quality synthetics). The oil ran cooler and the idle oil pressure was greater with the 5W-40 oils than with the xxW-50 oils.
The 5W-30 oils were only a tad behind the 5W-40 oils and the only reason I did not end up using these was the oil consumption at the track was 1.3 Qt/day versus 0.6 Qts per day with the xxW-40 stuff. If and when this car gets taken off the "always track ready" status, it will go back to a 5W-30 oil and I may even try a 0W-20 oil to see how the guages and the car responds.
*A thin xW-40 oil is 13-14 cSt at operating temp.}
The 5W-30 oils were only a tad behind the 5W-40 oils and the only reason I did not end up using these was the oil consumption at the track was 1.3 Qt/day versus 0.6 Qts per day with the xxW-40 stuff. If and when this car gets taken off the "always track ready" status, it will go back to a 5W-30 oil and I may even try a 0W-20 oil to see how the guages and the car responds.
*A thin xW-40 oil is 13-14 cSt at operating temp.}
Although we don't get as constantly hot as Texas or Arizona, it does get hot here in the summer. Combine that with traffic jams that make SoCal's (or metro D.C.'s) "parking lots" look like fun, and I see his point. I even went to RL 5W-40 (a very thick 5W-40!) for the summer. We DO need big HTHS and TBN here!! That being said, in his engines I would not go thicker than a 10W-40 (dino or synth.). Too bad he did not catch the PennzPlat sale/rebate at Pep Boyz (under $2.00/QT.).
I bought some 20w50 Synpower that I may use to fortify either 10w30 or 10w40 (depending on the vehicle) by adding one quart 20w50.
Should I be worried since I use 5W-30 (either Havoline or Castrol)year round in Tennessee. My 1996 Avalon has just over 186,000 miles and doesn't use an appreciable amount of oil between 5K OCI's. Admittedly, I don't drive it hard. The car has a factory temp gage and it always points to the same place when up to temp. I thought that cooling systems were supposed to keep temps at a constant max range. ??
John
John
Yeah, I run 20W-50 (actually M1 15W-50) in the summer . . . in my marine engines.
But I think in your engines, a 10W-30 is more viscosity than you will ever need for the very hottest Jersey summer days . . . unless you plan on running WOT uphill for hours on end.
Feel comfortable with it. I run 10W-30 in all our vehicles year round.
I used 20w50 year-round for my VW Jetta, but that is what the owners manual called for. I would be hesitant to put it in something intended to use 10w30. 10w30 is a very good oil, i dont see a reason to go away from it with your current applications.
Your engine may run HOTTER with 20w50 than it would with 10w30 due to the increased friction. If you are worried about heat during the summer, flush your radiator, that would do more good than switching to 20w50.
Your engine may run HOTTER with 20w50 than it would with 10w30 due to the increased friction. If you are worried about heat during the summer, flush your radiator, that would do more good than switching to 20w50.
I think your car is kept at whatever temp the combined effort of the electric fans and thermostat keep it at.
Your Avalon was meant to run on 5w30 or 10w30, and your success at 186,000 miles proves that what you are doing is working perfectly.
JHZR2
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20w-50 is really overkill...
I dont see an issue with running a 5w-40 oil in most anything though...
The real determinant is if YOUR engine shows increased wear in OCI... if YOUR oil pressure changes due to thinning of the oil, and if YOUR oil life is significantly reduced due to operating conditions... I think not, most likely.
Coolant temperature control in modern cars is pretty darn good. The actual difference between a traffic jam at 75 degrees, which isnt that hot, and 100 degrees, which on even the worst shore traffic weekend on the parkway, youll likely not encounter... is relatively small, compared to the oil temperaure, which is over 212 degrees.
Het load due to inefficient combustions, hard driving, etc. is a bigger issue... and at the end of the day, likely the engine is designed for optimal cooling atound 100 degrees, for overall robustness of design.
JMH
I dont see an issue with running a 5w-40 oil in most anything though...
The real determinant is if YOUR engine shows increased wear in OCI... if YOUR oil pressure changes due to thinning of the oil, and if YOUR oil life is significantly reduced due to operating conditions... I think not, most likely.
Coolant temperature control in modern cars is pretty darn good. The actual difference between a traffic jam at 75 degrees, which isnt that hot, and 100 degrees, which on even the worst shore traffic weekend on the parkway, youll likely not encounter... is relatively small, compared to the oil temperaure, which is over 212 degrees.
Het load due to inefficient combustions, hard driving, etc. is a bigger issue... and at the end of the day, likely the engine is designed for optimal cooling atound 100 degrees, for overall robustness of design.
JMH
10-30 since your car is the one of the only GM motors still spec'd 10-30. The rest were spec'd 5-30 by 1996 and GM used 5-30 for your motor for a few years and then went back to 10-30 but only on the 3.8.
I use 10-30 in 3.8 GM V6 Lesabre in California in very hot, stop and start long commutes. No problem -good numbers. 20-50 is for a car using 2 qt of oil every 500 miles and a few old english motor cycles. If your 2003 has those symptoms I'd use the warranty to stop the flow not 20-50.
I use 10-30 in 3.8 GM V6 Lesabre in California in very hot, stop and start long commutes. No problem -good numbers. 20-50 is for a car using 2 qt of oil every 500 miles and a few old english motor cycles. If your 2003 has those symptoms I'd use the warranty to stop the flow not 20-50.
I used to run 20-50 all year round, years ago.
That was a huge mistake, even in summer.
That was a huge mistake, even in summer.
20w-50? Sure, it'll work on some engines, at some temperatures. My daily driver is a 1995 E320 Mercedes Benz. It has used Pennzoil dino 15w-40 for most of its life, but has also had some 20w-50, too, when a previous owner had it.
Dealer seemed to prefer 20w-50. Local indy shop seems to prefer 15w-40.
Dealer seemed to prefer 20w-50. Local indy shop seems to prefer 15w-40.
The reason I ask is because I know that back in 1984 is when GM started the campaign that higher weight multi-viscosity oils such as 10w 40 and 20w 50 causing harm really had to do with corporate average fuel economy imposed by Uncle scam by mandating use of lighter-weight 5w 30 and 10w 30 in it's new cars. Doesn't 5w 30 have the same amount of viscosity-extending polymers as 10w 40 and 20w 50?
20w50 has less VII's due to the fact it starts with a heavier oil (20).
JHZR2
Staff member
much of this is a non-issue with the modern formulated oils, more shear stable VIIs, etc.
Seriously, take a look at some UOAs with your same oil... its a good place to start with selevting oil... you dont have that much more severe use than anyone else.
JMH
Seriously, take a look at some UOAs with your same oil... its a good place to start with selevting oil... you dont have that much more severe use than anyone else.
JMH
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