I’ve been using premium gas for my 98 Dodge Neon RT since I bought it back in 2002 or so. I recall it being recommended by the manufacturer but I don’t have a copy of the manual anymore so I’m not sure. My friend says I don’t need it, but I feel like I’ve heard somewhere that DOHC engines need to run the higher octane gasoline. Mine’s a 2.0L DOHC. I don’t use the more expensive gasoline because I’m looking for “extra performance”, but because I think it’s recommended to avoid inefficiencies, like knocking. Would like your opinions to settle this–thanks!
Octane need is more about compression.
When there’s very little left in the tank, try out a half tank of regular , turn off your radio or take out the earbuds, and listen for your engine to tell you if it likes it or not.
If you hear it pinging, or kackling ( mostly during acceleration ), top off with, and keep using your usual.
One tank full won’t harm anything, just dont drive for months on end with continuous pinging and kackling. My 80 Bronco blew a hole through the top of a piston from using too low an octane for too long of a time.
Yea, check the owner’s manual. If you can’t find your, then shame on you. You may be able to find one on the internet. Buying higher octane will not help nor will it give you any benefit, but it will cost more.
If you have knocking, you need higher octane.
There’s nothing special about a DOHC engine. It just makes the engine more efficient. The engine isn’t a high compression engine nor is it a forced induction engine. So there’s no reason to use a high octane or premium gasoline in the engine.
Tester
Why don’t you just get a manual? How have you been able to maintain the car properly when you don’t know what needs to be done?
If the inside of fuel door states use PREMIUM only then use it. If it just states use regular that is fine.
A 98 Neon would only get the cheapest regular if I owned it.
IBID. Check the fuel door…should have the minimum octane rating listed right there. Won’t say “regular” or “Premium”, but 87 (regular), 91, or something else.
In your testing to see what fuel makes it happy, don’t forget the mid-grade option.
Edit: Or call the dealer and ask. 
Thanks for your replies. I was able to get someone to scan a copy of the gas section in the manual. It displays an image that shows 89 as the minimum octane but then states that any fuel between 87 to 91 may used, where 91 would provide maximum performance. A little confusing, I guess, but I guess it confirms that 87 is fine.
I’ll probably try tapering down to 89 first, then to 87 just to see if I can notice any differences. Thanks.