Is Super Unleaded Gas Necessary? (1 Viewer)

St. Widge

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I have a Mazda CX7 which has a turbo charged 4 cylinder engine. When I got it, the EPA millage was supposed to be 27 miles per gallon so I thought it would be a good gas savings from my 4Runner which got about 18 miles per gallon. I knew that the manufacturer said that I had to use Super Unleaded gas with the turbo charger, but I figured the 9 miles per gallon difference would more than make up for that. Unfortunately, the CX7 really only gets about 20 miles per gallon. I like the car and it handles really well with the Turbo Charger and sport tuned suspension, but Super Unleaded gas at 20 miles per gallon is not much fun.

Anyway, does anyone here know if I really need to use Super Unleaded with a turbo charger? If not, can I use regular? If I use regular would their be any long term consequences? FWIW, I've put regular and plus in it once in awhile, when I was forced to use a station with really expensive gas, and did not notice any performance difference.
 
Super is for high compression engines usually. Sometimes it is just recommended by the OEM because the vehicle won't meet the stated performance and fuel economy specs with regular. Try using regular, if you don't get any knocks, ping, or valve clatter, you should be fine. I you do get any of those symptoms, just switch back.
 
Mandi has a 350z and I almost ran out of gas and the station where I stopped only had 87 octane. I put a couple gallons in until I could get to another gas station and it went from a finely tuned sports car to the acceleration of mule with no rear legs. Not only did it run like crap but it made some serious pinging noises. I don't know if it will have the same impact on your car but I certainly wouldn't try filling up a full tank of regular. Just put a couple gallons the next time you are on empty and see what happens. It wont hurt the car you just may not like the results.
 
Super is for high compression engines usually. Sometimes it is just recommended by the OEM because the vehicle won't meet the stated performance and fuel economy specs with regular. Try using regular, if you don't get any knocks, ping, or valve clatter, you should be fine. I you do get any of those symptoms, just switch back.

Thanks. That's what I was thinking but wanted someone who knew something about engines to confirm it. I didn't have a problem using "good" gas for awhile and even used it sometimes in my 4Runner, but gas prices have gotten so out of control it's hard to justify the extra 20 or 30 cents per gallon. Especially since I drive an average of 400 to 600 miles per week.
 
All I know is that my Monte Carlo Z34, with a high output 3800cc V-6, drives like a milk truck when I use 87 octane and takes its dear sweet time getting up to 70. With 93 octane, it zips up to 70 and tries to go 80...it's like I have to hold it back. Runs like a completely different car.
 
Mandi has a 350z and I almost ran out of gas and the station where I stopped only had 87 octane. I put a couple gallons in until I could get to another gas station and it went from a finely tuned sports car to the acceleration of mule with no rear legs. Not only did it run like crap but it made some serious pinging noises. I don't know if it will have the same impact on your car but I certainly wouldn't try filling up a full tank of regular. Just put a couple gallons the next time you are on empty and see what happens. It wont hurt the car you just may not like the results.

I've tried it before and didn't notice any performance difference. The CX7 4 Cylinder turbo charged engine has as much or more power than any 6 cylinder I have driven and I didn't notice any power drop off or pinging. And, I drive like a maniac so I would have noticed hesitation. I just wasn't sure if it would cause any long term damage to the engine.
 
OK, everyone will think I'm making a joke here but I'm asking this seriously. :hihi:

What effect if any will different grades have on my mini van?
 
OK, everyone will think I'm making a joke here but I'm asking this seriously. :hihi:

What effect if any will different grades have on my mini van?

If the higher is not recommended by the manufacturer, you'll get ZERO benefit from putting higher octane gas in an engine that only needs 87. Not even as a "treat."
 
Higher performance engines are designed with a certain minimum octane in mind. You can get pinging with lower octane, and I'm almost certain that Mazda uses knock sensors to detect pinging and retard timing in case of lower octane fuel.

If your gauge cluster or fuel door/fuel cap say PREMIUM UNLEADED ONLY, you're probably better off just biting the bullet and putting the good stuff in.
 
We have a CX7 also. You are supposed to drive with the mid grade not super unleaded.
 
The OCD in me tells me that there is only one tank of gasoline beneath the gas stations and it flows to to all three nozels above.

/conspiracy.
 
i have a bunch of crap (i say crap because listing would take forever) done to my camaro and when i put S.Un. in it, it drives like an ANIMAL, regular unleaded makes it lag.. i hate to say it but it does make a difference, but if your just riding around town, i don't think it matters...
 
i have a bunch of crap (i say crap because listing would take forever) done to my camaro and when i put S.Un. in it, it drives like an ANIMAL, regular unleaded makes it lag.. i hate to say it but it does make a difference, but if your just riding around town, i don't think it matters...

It depends on the compression ratio bro.
 

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