What kind of gas should I use in this SUV

reg, is fine and that is what is recommend, using Prem is only draining your wallet faster. Now if you do some engine up-grades you might want to go up a grade. The ehgine is just a Chev truck engine (same as the Avalanche and there full size trucks) Best of luck

You can also not put gas in it anymore, sell it and buy something less guzzling?

you can use reg , but on most trucks that have the 6.0 liter ,GM Recommands using the higher grade because it helps the engine run alittle better and also the better gas you put in , the better gas mileage you get. Most of GM Trucks cam with the 5.3 not the 5.7 in that year.

They actually quit putting the 5.7 litre in pickups in 1999. In 2005, the engine choices would have been the 4.3 liter V6 (262), the 4.8 liter V8 (292), the 5.3 liter V8 (327), and the 6.0 liter (364). So, while the 6.0 liter was usually put in heavy-duty trucks, it was offered in the Chevy pickups in 2005. However, it was almost certainly tuned differently for the Denali and Escalade applications. Oh yeah, regular ought to be fine for it.

Premium

Premium

Just use what the manufacturer recommend and you will have less problems. For the extra $.50 cents a gallon it will benefit you in the long run.

I have my 2016 Escalade ESV and I feel the difference. I've used regular gas and engine is sluggish and when I hit the gas hard jumps before it takes off. When I use the premium thing is like a sewing machine flushes off quickly with no hesitation so I feel the pain that you haven't LOL I wish I can put regular too but premium is the way to go.

The 6.2 Escalades/Denalis need 93 thanks to being a high performing engine. The older 6.0s run ok on 87/89 and that's what I been running for years and have a perfect engine at 235k. Some are even E85 flex fuel too. I'm almost certain the 6.2's from 07-14 were E85/Flex too but I'd have to look it up.

My '11 Escalade is a dog and runs horrible on regular. I've had Mercedes, etc that wanted premium and I always used regular and there was no difference. The Escalade is completely different. I wasn't very happy about it because premium is so much more expensive and I go on long trips. But it NEEDS premium. There's no way around it.

The 2007 to the '13 had the 400 hp engine which will run on regular because it has a knock sensor that will retard the timing when you get detonation. You are better off running a higher octane fuel.

I have a 1999 Cadillac escalade can i put regular gas in it