2003 Cadiilac Escalade AWD 6.0 realistic performance upgrades?
 

I bought a 2003 escalade 6 months ago. It has 110k miles on it. I runs great and was driven by an elderly man. Garage kept and kept up with.

After the last 6 months I've really enjoyed driving this SUV (not as much as my 88 Fleetwood Brougham) and I want to upgrade the performance on this SUV in a realistic way. I understand that this is a 3 ton SUV and is never going to be a corvette or dragster.

I'm looking to take less wear off the engine and transmission and higher my gas mileage.

I've read through some of the threads and it seems a lot of the things you would normally do to like a Toyota would not help in a 6.0 engine???

My brother-in-law said to add a cool air intake and it would raise it like 5 mpg? and to upgrade the spark plugs and use synthetic oil to lessen wear on the engine. In my conversation with a few mechanics they've told me those two factors really done matter as long as you regularly change your oil and make sure the spark plugs don't "burn out"

I am very car illiterate! So I could use the help on what direction I should go with making it last.

Thank you

Synthetic oil is great if you use it from when your engine is brand new. While their is still benefit in using it in an engine with 110k miles, you won't benefit as much as if it has always been used. The new iridium spark plugs last a long time but if they have never been changed, you should replace them. The cold air intake is a good upgrade but it will NOT give you anywhere near 5 mpg. You may see 1-2 mpg at best. You can buy a handheld programmer if these are all the mods that you will be doing. It should help with throttle response and drive ability. I suggest Diablosport if you get one. You should be able to find one used on EBay. If you ever plan one doing any more detailed mods like headers, throttle body or intake upgrades, spend the money and get a custom tune. Hope this helps.