derkach99 Posted July 6, 2014 Report Share Posted July 6, 2014 Just a quick question what is the best and safest gas to put in a 3.1L the cutlass? I find with supreme gas gas mileage is noticeably better but I hear it's dangerous for the car. Quote Link to comment Share on other sites More sharing options...
Schurkey Posted July 6, 2014 Report Share Posted July 6, 2014 Just a quick question what is the best and safest gas to put in a 3.1L the cutlass? I find with supreme gas gas mileage is noticeably better but I hear it's dangerous for the car. Not dangerous. Well, not any more dangerous than any other gasoline. If the fuel has more octane than the engine needs, you're wasting money. If your fuel economy increases with premium, I suspect either knock-sensor problems or carbon deposits in the combustion chamber. Next time you do an oil change, before you dump the old oil, squirt a "urine stream" of water from a garden hose into the throttle body while someone holds the gas pedal just below the rev-limiter (3000 rpm?) with the transmission in "park". The water will steam-clean the combustion chambers very nicely. Tends to put moisture in the oil, which you're going to change as soon as you've run a minute's worth of water through the engine. You could do the same thing with a quart squirt-bottle, but it takes longer and you'll have to re-fill the bottle a few times. If that doesn't reduce the knock-sensor activity, perhaps the sensor is defective (or the wrong part installed in your engine), or the engine has other problems like partially-clogged fuel injector(s) or low fuel pressure that leans the mixture some. A few minutes with a REAL scan tool would answer many questions. Quote Link to comment Share on other sites More sharing options...
derkach99 Posted July 6, 2014 Author Report Share Posted July 6, 2014 Well i heard using a grade of fuel higher then what your engine is designed for can lead to trouble after consistent use. Quote Link to comment Share on other sites More sharing options...
tornado_735 Posted July 6, 2014 Report Share Posted July 6, 2014 Nope. Using a fuel grade less than recommended though, that's where you have problems. Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted July 6, 2014 Report Share Posted July 6, 2014 whoever you're hearing this stuff from? stop listening. these sound like the same people that think without exhaust backpressure, you'll burn valves or some other hocus pocus shit that has been passed down through the past couple of decades. Quote Link to comment Share on other sites More sharing options...
Nas Escobar Posted July 7, 2014 Report Share Posted July 7, 2014 I would run regular and be done with it. I run regular on mine. Quote Link to comment Share on other sites More sharing options...
derkach99 Posted July 7, 2014 Author Report Share Posted July 7, 2014 Supreme gas is safe for for my car! Quote Link to comment Share on other sites More sharing options...
Nas Escobar Posted July 7, 2014 Report Share Posted July 7, 2014 I've ran supreme before... if the car's tuned to regular, it won't matter much. Don't run race fuel on it though, anything past 93 octane, you'll burn up the cat. Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted July 7, 2014 Report Share Posted July 7, 2014 I've ran supreme before... if the car's tuned to regular, it won't matter much. Don't run race fuel on it though, anything past 93 octane, you'll burn up the cat. ......... huh? you can run any type of gasoline through it, but if it is leaded, expect your cat and O2 sensor to quit working shortly after or at least has a noticably shorter life. when you start mixing in stuff like toulene, benzene or other interesting chemicals, that will get you in trouble too, but it isn't the cat i would be worried about. you can get non-leaded 100 octane gas, but i've never gotten ahold of anything beyond that. aviation fuel(avgas) tends to be high octane and by law, ethanol free. not cheap though, certainly not worth using in the average engine. Quote Link to comment Share on other sites More sharing options...
tornado_735 Posted July 7, 2014 Report Share Posted July 7, 2014 I ran leaded 112 octane through a 1995 Ford Aerostar with the 4.0L V6...I can only imagine how fast it ate my cat. Quote Link to comment Share on other sites More sharing options...
Nas Escobar Posted July 7, 2014 Report Share Posted July 7, 2014 ......... huh? you can run any type of gasoline through it, but if it is leaded, expect your cat and O2 sensor to quit working shortly after or at least has a noticably shorter life. when you start mixing in stuff like toulene, benzene or other interesting chemicals, that will get you in trouble too, but it isn't the cat i would be worried about. you can get non-leaded 100 octane gas, but i've never gotten ahold of anything beyond that. aviation fuel(avgas) tends to be high octane and by law, ethanol free. not cheap though, certainly not worth using in the average engine. I've been told that high octane fuel will end up messing up the cat... Whether or not it's leaded is another subject, but it seems there's a defacto consensus to not run racefuel. Quote Link to comment Share on other sites More sharing options...
tornado_735 Posted July 7, 2014 Report Share Posted July 7, 2014 I've been told that high octane fuel will end up messing up the cat... [video=youtube;1Tfoa4Fz-WU] Quote Link to comment Share on other sites More sharing options...
Nas Escobar Posted July 7, 2014 Report Share Posted July 7, 2014 Had to take it all the way there huh? Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted July 7, 2014 Report Share Posted July 7, 2014 toluene and xylene are just really good gasoline. mixed with reg gas will make it premium basically, if you took out the corn water it would be even better. Quote Link to comment Share on other sites More sharing options...
pitzel Posted July 7, 2014 Report Share Posted July 7, 2014 Just use 87 or whatever. The 3.1 is not a high compression engine. If you run into any meaningful amount of knock issue, it is likely something else wrong with the engine. Higher octanes will actually reduce fuel efficiency (increase consumption). Seriously, its the 3.1L, utilitarian, not exactly a performance engine. Save your money and buy a real car when you can afford it if you're looking for more performance, as there's very little that can be done to these engines short of replacing them. Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted July 7, 2014 Report Share Posted July 7, 2014 yeah, what year cutlass anyway? the description really doesn't help narrow it down any Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted July 7, 2014 Report Share Posted July 7, 2014 Just use 87 or whatever. The 3.1 is not a high compression engine. If you run into any meaningful amount of knock issue, it is likely something else wrong with the engine. Higher octanes will actually reduce fuel efficiency (increase consumption). Seriously, its the 3.1L, utilitarian, not exactly a performance engine. Save your money and buy a real car when you can afford it if you're looking for more performance, as there's very little that can be done to these engines short of replacing them. the 3.1 was first tuned by McLaren I thought. Quote Link to comment Share on other sites More sharing options...
Night Fury Posted July 7, 2014 Report Share Posted July 7, 2014 Aaron, thanks for wasting a half hour of my life forcing me to look for a video of Coleco Talking Teacher saying "apostrophe" Of which I failed miserably. WHY DOES THIS NOT EXIST Quote Link to comment Share on other sites More sharing options...
derkach99 Posted July 7, 2014 Author Report Share Posted July 7, 2014 I drive a 1994 cutlass in blue. Sent from my iPod touch using Tapatalk Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted July 7, 2014 Report Share Posted July 7, 2014 I've been told that high octane fuel will end up messing up the cat... Whether or not it's leaded is another subject, but it seems there's a defacto consensus to not run racefuel. it's not that it has a high octane rating, it's how that octane rating is achieved. you can make some wicked octane levels with "gasoline" if you pour pure isopropyl alcohol into it. that has a AKI octane rating of 108. but then you'll run into the issue of increasing levels of iso causing the stoich AFR to droop badly, which the O2 sensor will only account so much for. iso has a stoich ratio of 11.4:1, which vs the 14.7:1 of pure gasoline is an increase of 29%. a tank of half 93 octane and half iso would make roughly 100.5 octane fuel with a stoich AFR of ~13.05:1. that is MOST LIKELY going to be within the limits of O2 sensor correction, but i wouldn't rely on that alone, recalibration would be by far the best path to keeping things happy. on an OBD1 vehicle, long-term fuel trims would eventually settle near a BLM of 144, which is usually right on the edge of the O2 sensor upper trimming limit. with OBD2, around +13% and i don't know where the limits are with those calibrations. certain fuels, when burned, produce large amounts of NASTY stuff in the exhaust, corrosive stuff that will eat away at the cat and everything else it touches. you're not likely to run across those without multiple indications that the fuel is meant for non-highway operation. Higher octanes will actually reduce fuel efficiency (increase consumption). ehh....... yes and no. comes down to how the fuel is blended. pure, 87 octane gasoline contains roughly 115,000 BTU of energy. E10 87 octane is 112,000. i can't find solid numbers for 91/93 octane fuel, but "sources" imply within 1% of regular gasoline numbers for ethanol-boosted and non-ethanol boosted premium fuel. Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted July 11, 2014 Report Share Posted July 11, 2014 I drive a 1994 cutlass in blue. Sent from my iPod touch using Tapatalk I just run premium clear gas in all my 1990's and 1980's cars and trucks. But that is because the vehicles I drive all run better on it. I would try using it in a 1994 cutlass as well or any early 90's car. Quote Link to comment Share on other sites More sharing options...
1990lumi Posted July 12, 2014 Report Share Posted July 12, 2014 i use 91 octane in my 3.1l 90 lumina just because its ethanol free and i get better gas mileage with it Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted July 12, 2014 Report Share Posted July 12, 2014 something interesting to think about: the difference between 87 and 91/93 octane fuel is about 20-30c/gallon depending on the trends in your area. let's say $3.50/gallon for regular and worst-case of $3.80/gallon for premium and you're getting a nearly full tank of fuel with 15 gallons(leaves you at least 1.5 gallons of reserve depending on the exact model of w-body). 3.5 X 15 = $52.50 3.8 X 15 = $57.00 so, for $4.50, assuming you have a really consistent route to drive, you can find out if premium is going to be beneficial or not. Quote Link to comment Share on other sites More sharing options...
1990lumi Posted July 12, 2014 Report Share Posted July 12, 2014 3.80 for premium i wish :/ here in central wisconsin gas is 3.74 for 87oct. with 10% ethanol Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted July 13, 2014 Report Share Posted July 13, 2014 wiki has this: In theory, all fuel-driven vehicles have a fuel economy (measured as miles per US gallon, or liters per 100 km) that is directly proportional to the fuel's energy content.[55] In reality, there are many other variables that come into play that affect the performance of a particular fuel in a particular engine. Ethanol contains approx. 34% less energy per unit volume than gasoline, and therefore in theory, burning pure ethanol in a vehicle reduces miles per US gallon 34%, given the same fuel economy, compared to burning pure gasoline. Since ethanol has a higher octane rating, the engine can be made more efficient by raising its compression ratio. In fact, using a variable turbocharger, the compression ratio can be optimized for the fuel, making fuel economy almost constant for any blend.[26][27] 26 -27 are the links to http://www.afdc.energy.gov/fuels/ government sites that.. 26 has info to e-85 alternative fuels. 27 has a dead link. sounds like a government scam Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.