My Lexus LS400 has over 300K miles on it. Whats the best engine oil for it? I live in Dubai and you know the climate is very hot here. Is this a good engine oil for it? please check the link

http://www.zic.co.nz/products/zic-hiflo/

 

Does the ambient temperature ever get below 50 degree's F there? And what is the hottest temp?
Also what kind of oil has been used in it? Is it regular motor oil or synthetic?

 

Keep using whatever you were using. Most likely regular dino oil should be good. Or you can use high mileage synthetic blends like valvoline or castrol gtx HM. Stay away from full synthetic

 

No the minimun temp goes around 18c the hottest is around 50c. And the regular engine oil used.

 

Why stay away from full synthetic?????

 

I say stay away from all synthetic. Why 300 K miles and its not been on it. Its high time and all syn type will easily leak.

Your temps are 64 to 122 degrees F ? So what oil has been running in it?
You could run something like 15w-40, straight 30 or 40. Or just go with what has been in it.
I have run 20W-50 in a high time LS in the summer here, and our temps hardly ever get into the 100's.

Local Mercedes dealer uses 5W-40, our temps here can dip into the below freezing in winter time so.

 

I'm running on Pennzoil ultra platinum synthetic. Car doesn't leak a drop of oil. Nothing wrong with synthetic. Mobil 1 has a $12 rebate on 5 quarts going right now. You can pick up 10 quarts for about $24. Get it while it's cheap.

 

LMFAO...totally untrue

 

Do a good search on it, its not untrue. I have a new car that leaked after using full synthetic.
Since I started using it I continue to do so. I will not use it on an old LS they came with normal
motor oil not syn.

 

then it exposed a weak spot..synthetic oils clean so u had buildup from using other oils..the high mileage on the car had nothing to do with it..and i dont need to research,im in the automotive business and its my job to know. i started using synthetic oil at 190,000..no leaks.

 

To each his own. If you like synthetics go ahead nobody is stopping you. I love synthetics but only if the car started using it under 100k miles. OP's car has been using dino oil for 300k and it's been good so far so why try something that may open up a can of worms? I did dino to synthetic conversion on my old acura with 120k . After awhile it started leaking oil. I used to be that guy who swore by synthetics no matter what. Only cars usings sythetics now is my prius and previously owned mercedes SUV since manufacturer recommends them. My z uses rotella T6 which I believe is not fully synthetic and I drive it hard. Now it has 155k miles and still no smoke or drop of oil.

 

Main problem when it comes to switching from conventional to synthetic is that conventional makes most of the seals and gaskets swell up, while synthetic makes them shrink. This is where people start seeing leaks.

I would not do it on a car with 300k miles.

Stick with oil that was recommended by people who made your car.

 

synthetic oils leak? never heard of that... mine has only ever been given mobil 1 5W-30 synthetic and has never had any problems

dicer your reasoning seems pretty dicey... i know they got that legal weed in washington now but you don't gotta go so hard on it

 

These engine oil threads are always amusing to read, because you will see so many different opinions on it! ha ha!.... but while i'm here:

Mobil-1, for the win!

 

He he he, you got the wrong guy for that stupid crap, and the name I use is an acronym.
I've got over 40 years experience with engine related and machinist stuff how about you?