What octane gas do you use? (The Mother thread)
09-06-07, 07:16 AM
#106
I use 87 & 93 in a 1:2 ratio when I fill up - I save at least $1 per fill-up that way and I still achieve the recommended minimum of 91. Hey, it adds up if you drive a lot. I estimate based on the fuel gauge reading (knowing that a full tank is ~21 gal.) and I always make sure I lean more toward the 93, so I end up with octane > 91. Also, the best time to fill up is early morning, or in cooler weather, to reduce the effect of heat expanding the volume of gasoline. Better for it to expand after it is in your tank ;-)
09-06-07, 07:26 AM
#107
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You DO realize the only reason I run it at all is to keep it running cleaner right? The marketing hype of 'octane boost makes you go faster' should have died out years ago; for some reason people still cling to the idea.
Believe me, I'm not going to pay the ridiculous extra cost of that stuff just because my or someone else's butt-dyno says so. I did the research, I know the only way I'll see a difference is with a higher compression ratio and aftermarket programming. Thanks for the information anyways though, a little expansion on the topic is always nice.
Here in southwestern AZ we practically live in 100-110+ all summer; I do what I can to treat the car. Early oil changes, good gas, etc.
Edit: I realized my original post might have been misleading. I've noticed since I began to run higher octane fuel through the tank that overall my throttle response is better than when I was first driving it. The first time I did it, I used a half-tank and the exhaust really stank; now it doesn't and my throttle feels right. I didn't intend to imply that a mere 1/4 tank of 100 oct fuel is making the car run better than when its all 91, that's just dumb.
Believe me, I'm not going to pay the ridiculous extra cost of that stuff just because my or someone else's butt-dyno says so. I did the research, I know the only way I'll see a difference is with a higher compression ratio and aftermarket programming. Thanks for the information anyways though, a little expansion on the topic is always nice.
Here in southwestern AZ we practically live in 100-110+ all summer; I do what I can to treat the car. Early oil changes, good gas, etc.
Edit: I realized my original post might have been misleading. I've noticed since I began to run higher octane fuel through the tank that overall my throttle response is better than when I was first driving it. The first time I did it, I used a half-tank and the exhaust really stank; now it doesn't and my throttle feels right. I didn't intend to imply that a mere 1/4 tank of 100 oct fuel is making the car run better than when its all 91, that's just dumb.
Last edited by mac6694; 09-06-07 at 07:36 AM.
01-22-11, 06:14 PM
#108
What gas do you use
Does everyone here actualy use premium gas as in 91 or higher. Im sure someone has atleast used 87/89 and can share thire experience, was there a big loss in gas milage and performance, im just wondering if its really worth the extra money for the good gas
01-22-11, 06:58 PM
#109
Long ago I experimented and the thread is buried somewhere here. The last 5 years or so only Shell Premium.
I vaguely recall it:
87- 20-21 MPG
89- 22-23 MPG
91- 24-26 MPG
The GPS calculated 25.6 MPG on the last 800+ mile run with Shell 91 . I'm pleased for a car with 160K miles on it. It works out comparably in cost though. I prefer longer intervals before having to gas up and the 91 gives that. I pull into the gas station on long runs at 440 miles and my usual in town somewhere around 280-310 miles depending how much stop-go is needed.
I vaguely recall it:
87- 20-21 MPG
89- 22-23 MPG
91- 24-26 MPG
The GPS calculated 25.6 MPG on the last 800+ mile run with Shell 91 . I'm pleased for a car with 160K miles on it. It works out comparably in cost though. I prefer longer intervals before having to gas up and the 91 gives that. I pull into the gas station on long runs at 440 miles and my usual in town somewhere around 280-310 miles depending how much stop-go is needed.
01-22-11, 07:19 PM
#110
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Yes you should be using premium gas. Worth the extra money for good gas? 
It's worth it not to be cheap. I wouldn't worry so much about mileage, but more what it will do to your engine. I'm sure, if you're asking this question, you have already used cheap gas so you know how it runs. I had some idiot pump a full tank of regular gas into mine at a full service. (It was a blizzard and I got lazy) I can't believe I gave him a tip. The car ran so bad it sounded like it was gonna explode. It would hardly make it up a small incline and the sound of the pinging was like the engine was falling out. I tried some octane boost, it didn't help. I ended up siphoning the garbage out and putting it in my kids car ('95 Corolla)
01-22-11, 11:16 PM
#114
Pole Position
I've been using 87 for the last year. Getting 16mpg all city same as when I was using 93.
Don't notice any difference in engine operation but I rarely go past 2K rpm. Times are tough need to save money.
Don't notice any difference in engine operation but I rarely go past 2K rpm. Times are tough need to save money.
01-23-11, 06:51 AM
#115
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I get the same gas mileage if i use shell 87, or shell 93.
I use 87 in my 95 ls400 90% of the time, usually after any kind of maintenance i will fill it up on 93 hoping to help in some way, it never has.
I use 87 in my 95 ls400 90% of the time, usually after any kind of maintenance i will fill it up on 93 hoping to help in some way, it never has.
01-23-11, 08:02 AM
#116
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Last edited by ariasuriah; 01-23-11 at 08:06 AM. Reason: broken link
01-23-11, 08:03 AM
#117
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01-23-11, 08:36 AM
#118
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As noted by the previous posts it's silly to think higher octane gets better performance etc in most cases but here are two things to think about when buying your gas:
Older high performance engines DO need higher octanes. Case in point my 91 LS400 pings with 87 but runs fine on 89, there is no need for 93. However my 03 A6 with a 300hp 4.2L V8 is just fine with regular 87. I suppose the knock sensors etc are just better at controlling detonation.
Secondly one way an ECU can deal with detonation is dial back the timing... this = a little less hp. so technically you might get a little more HP but only because the engine is retarding the timing a tad to compensate for the knock. I imagine it's hardly noticeable and certainly not detectable by your "butt dyno"...
In short, run the lowest octane you can run without the engine pinging and save the $$$ for maintenance. Some cars will handle lower octane better than others.. in general it seems the newer ones handle it better than the older higher performance engines. Just get the gas from a decent chain like shell, mobil, hess, exxon etc etc etc
Older high performance engines DO need higher octanes. Case in point my 91 LS400 pings with 87 but runs fine on 89, there is no need for 93. However my 03 A6 with a 300hp 4.2L V8 is just fine with regular 87. I suppose the knock sensors etc are just better at controlling detonation.
Secondly one way an ECU can deal with detonation is dial back the timing... this = a little less hp. so technically you might get a little more HP but only because the engine is retarding the timing a tad to compensate for the knock. I imagine it's hardly noticeable and certainly not detectable by your "butt dyno"...
In short, run the lowest octane you can run without the engine pinging and save the $$$ for maintenance. Some cars will handle lower octane better than others.. in general it seems the newer ones handle it better than the older higher performance engines. Just get the gas from a decent chain like shell, mobil, hess, exxon etc etc etc
01-23-11, 12:03 PM
#119
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I tried both 87 and 93 Octane in my '92LS 400. The 93 gave me almost 3 extra MPG in town driving. I have not driven the car much on the open road - so I dont know how much better the MPG will be here.
The car also seems to have better performance, although I did not have any pinging or
other sub performance issues with 87. There have been some posts on this site about premature wear on O2 sensors and other parts from using '87. 93 is OK for me @ 3.25per gal, but at 4 or 5 bucks per gal -- I will have to re-consider. Summer driving may be a rude awaking for many people this summer if gas price perdictions come true.
The car also seems to have better performance, although I did not have any pinging or
other sub performance issues with 87. There have been some posts on this site about premature wear on O2 sensors and other parts from using '87. 93 is OK for me @ 3.25per gal, but at 4 or 5 bucks per gal -- I will have to re-consider. Summer driving may be a rude awaking for many people this summer if gas price perdictions come true.
01-23-11, 12:57 PM
#120
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Just because you can run 87 in your LS and you do not hear it ping does not mean it is not happening. The knock sensors with pick up the ping that you may not hear. Since the 1UZ engines are a higher compression engine, it is HIGHLY recommended that you run 91 or higher like the owner manual states.
James
James