1997 Expedition EB on Castrol 10W-40

Hi All,

I'm currently living in Dubai, and am looking for information on what Oil to use in the used car I just bought and came across posts here.

The car's a 1997 Ford Expedition Eddie Bauer 4x4 (5.4L) with 90k kms on it. I know a bit about cars, done oil / spark plug changes myself and enough to work out that this was in good shape for an old car.

Dubai's weather is hot. We're talking 30c+ all the time, very often to 40c and a few times to 50c where the government declares a public holiday

Anyway, the owner's manual says SAE 5W-30 but I can't find anything in any auto shops or k-mart type stores here. The closest I can find is a local brand 5W-40, a shell 5W-40 and Castrol Magnatec 10W-40 A3/B3.

A mechanic someone recommended says he puts 20W-50 in everything here because of the weather, but I wasn't sure so I rang the Ford Dealers here and they said they get supplies of 10W-30 and they use that in all the Ford 4x4s. Its quite expensive compared to the magnatec 10W-40 so I was trying to work out if I 10W-40 would be ok.

I understand that its a semi-synthetic oil, but I'd like your take on this? Is it ok to use this oil in my car? Would it actually be better considering the weather?

I found this about someone who put 10W-40 in their expedition and the advice they got worries me ->

You've got one of the few vehicles that requires very light weight oil and you've put in the stuff that's so heavy that no one says you should use it anymore. I think this is a bigger deal than everyone, OK, most people here, are suggesting. I'd drive straight to the oil change shop and get it changed out ASAP. No need for additional cleaning though, just get it changed.

Every mile you drive with this heavy oil could be causing severe, irreversible damage to your engine. Just going the 3,000 miles to the next change could very well be enough damage to have to replace the engine . . . but . . . there's a chance that it could be fine too.

Is it worth saving $25 on an immediate oil change to gamble a $4,000 engine?

I'm so serious about this that I wouldn't drive it anywhere but to the shop to get the oil changed. Better yet, do it in the driveway yourself. You might want to ask someone else to help you than the genius that thought 10w-40 would be good though