What motor oil weight to use for tropical climate?
 

We've had this discussion in the past back when I had the XK8, but I wonder if there is any difference with the XKR.

The car is currently running 5W-30 Mobil 1 synthetic oil. I am currently waiting for a used lower oil pan from ebay (mine is damaged, dented, and leaking), an OE lower oil pan gasket, and a Royal Purple 20-2009 extended life oil filter with anti drain-back valve.

Year round temperatures in Puerto Rico fluctuate between 70º to 90ºF, with a low of about 60ºF in the mountainous regions during "winter", and a highest temperature record of 103ºF in the south.

The 5W-30 is probably too thin for these climate temperatures. Would 10w-30 or 15-30 be a better option for my climate? I want the best protection for my engine.

do you have the full compliment of owners manuals ? In one of them*** there is an illustration showing which oil weight is recommended for various climates. IIRC, there are two suggested that correspond to your climate, one is the 0w-40. , the other is 5w-40 . Someone posted that manual illustration recently IIRC.

I use Mobil 1 0w-40 year round, and get the oil tested after every oil change. So far the Mobil 1 0w-40 is doing a great job, and the lab tells me to "...keep doing whatever I'm doing...." as the tests are showing that the oil is standing up very very well in my daily driver '02 XKR.


Z.

PS ***according to my 2002 Vehicle Care manual section 3-7, if the lows are in the 50 (F) range and the highs are in the 100's (F) or higher, the recommended oils are the0w-40 on the low end of that range and a 5w-40 for the upper range.

Giandanielxk8,

I'm in Bahrain, which is a hot desert climate so I appreciate your concern about the impact of a tropical climate. I used the previous 2011 thread, below, in choosing my recommended engine oil for the summer. I'm not picky on brand so long as it's synthetic.

https://www.jaguarforums.com/forum/s...nfusion-51004/

As my car is a daily driver, I actually change the oil 2x a year, so I go for the thicker oil 5W40 for the extreme summer temperatures here. Looking at the chart in the thread above, (double check in your owner's handbook) your 5W30 choice seems fine all year round. I presume you're not having any engine trouble to date.

There is some good general practise, that as our engines age, with high mileage, sometimes a thicker (ie higher numbers) are better. But then it's hearsay, with a similar debate on older cars, as to whether it's good to start the car, and let the car run warm at idle, before driving. I would guess we're not at that age yet.

Zray's use of a lab is brilliant, but I guess you and I don't have that kind of facility available to us.

No, unfortunately I don't have the manual. All I have is the pdfs from the sticky, but god knows where in my computer I put that.

No, I'm not having any engine trouble at all. I guess I'll either change to the 5w-40 or keep using the 5w-30.

my vote is also with the 0W-40 for two reasons. the XKR will heat the oil a little more and higher humidity lessens heat transfer so it might be a little more difficult for your engine to cool its oil. the temps that you provide are not ridiculously high. they are similar to summer temps where i drive. i would use the 0W-30, however there are many hills in my drives, some of them rather fun. the oil pressure was a little lower at operating RPMs than i liked after pushing the car on these roads. under these circumstances there was never a low oil pressure alarm at idle and only consumed 1/2 quart over five thousand miles. this could be from a sweating seal, and even a full quart of use would be no issue. be careful with the 5W-40s as they are often intended for diesels and not as good for gasoline engines. it is a leftover from an earlier time. any XW-40 within the same product is the same at operating temp which is why 0W-30 is often beneficial for for a 5W-30 specified car as it is better at startup. stay away from weird oils like Royal Purple and racing products. use Mobile 1, perhaps Amsoil and a good filter and you will be fine.

Now I'm confused, do I want thicker oil for warm climates or thinner oil?

ideally you want the same oil and perhaps slightly thicker for warmer conditions. the 0W-40 as Zray uses will be perfect for your car and usage.

the point is that most people assume that higher ambient temperature is more of a big deal than it actually is. it is only a problem if you operate in an unbelievably hot desert. even then if the car is able to maintain its cooling ability, there is not much of a need to use thicker oil.

Thanks! I've been seeing 0W-40 more often in stores lately, so it shouldn't be too much of a hassle to find.