Hello all,

I always put premium in, usually 93. However I filled up yesterday and the knucklehead working the pump put in regular 87. I know its not bad enough on one tank to warrant siphoning it out.

I wasn't sure if I should burn half the tank then refill with premium...

Or run the tank til empty then start fresh.

Thanks

 

The only way you can run regular grade octane safely is if your engine's compression is failing. Take it easy on the throttle and RPM, keep them both low until you burn it off, and top off with 93 when you can to start bringing the average octane up. Too low of octane can, and will, shatter your seals if you romp on it.

 

alright, ill take it easy on the engine til i can make enough room, should be down to 3/4 after the drive home 35 mile commute sucks

thanks for the quick response

 

I remember back when I was looking to buy an 8, one of the ones I took for a test drive was really low on gas so the sales guy came with me and we stopped to get gas.
He started putting 87 in and I tried to tell it had to be 93 and he said "That's not actually true, you only have to use 93 if the person who originally had the car used 93 from the beginning". Rather than try to explain what a rotary engine was to him, or the many flaws in his theory/lie I just asked him to take me back so I could leave...

 

I am glad I bothered to check the receipt, think it's worth trying to snake a hose down and siphon it out then?

And how high is too high on the RPM's I do all highway driving and 80mph is give or take 4k.

 

It's all relative based on factors that we don't have access to.

Compressing the air/fuel mixture heats it up. The higher the compression the more heat is generated. At some point, it will be hot enough to auto-ignite the fuel. Octane basically keeps raising this threshhold of where it will self ignite. A healthy 10.1:1 compression Renesis will heat the charge enough that it will auto-ignite a mixture with 87 octane. The ECU can compensate to a degree with timing changes, and at lower loads and RPMs there is less risk of that auto-ignition being a detonation that destroys seals. The more air you shove into the engine, the harder and bigger the detonation and the greater a risk you will run. A full throttle pull to redline on 87 octane and a healthy engine will almost certainly result in blown seals.


An engine that is lower compression on all 6 faces can run a correspondingly lower octane safely, because there simply isn't as much compression, so less heat. An engine with low compression on 1 face and healthy compression on the other 5 can't run lower octane safely. An engine with low compression on 5 faces and healthy compression on the 6th can't run lower octane safely.

But still, it's not something that we can say "this RPM or this load is fine". Just, take it easy until you can get higher octane in there.

 

Perhaps it's because I'm paranoid and OCD when it comes too the Renesis, but if it were me I would probably siphon it out...
Just not worth the risk.

 

What about octane booster?

 

I would siphon the gas or just run it through before I started dumping tons of that crap in to try and raise it.

 

Grab a bottle of octane booster and look at how many points it increases your octane by. Typically, they state 2-4 points. 1 point is 0.1. So in order to bring it from 87 octane to 93 octane, you need 60 points. At $5 a bottle, you are looking at maybe $100 worth of octane booster.

93 octane is cheaper.

 

Guess I'm taking it easy the next week or two to wor

 

Plus in that massive of a quantity wouldn't it cause all kinds of secondary problems?
Not to mention you would probably have to siphon some of the gas to get it all in...

 

It depends on what all is in it

 

I'm gonna have already done 60 miles, so I have prolly 3ish gallons used up already

 

siphon it and give it to me..

 

Just went out there and tried to siphon it out to put in my wife's car to no avail, the hose kept getting stuck, pulled it out and it was not even wet. Gonna drive it easy tomorrow to and from work, when I get home and fill it with 93, it should bring me up to 90.

I did a math estimate and figured out I put 12.8 gallons of 87, so i should have 3.1 gallons of 93 left in there. So the tank should be around 88 now.

I can put in 6.5 gallons of 93 in tomorrow giving me 90.

 

I wouldn't say its bad if you mixed it with a lower octane gas by accident, just drive it until its almost empty and put the 93 octane back in it.

 

I am taking it very easy on the way to and from work, but keeping it at 65 just doesn't feel right haha. Gonna push it one more day, then I should be putting in 9-10 gallons of 93 should get me above 91 at least.

 

Go to the hardware store and get a couple gallons of Xylene. It actually increases octane unlike the crap that you can buy from your local auto parts store.


If you're at half a tank it looks like 1 gallon would bring you up to about 93 or 94 octane.

 

The 8 specifies 91, not 93. The S1 owner's manual also says you can use 87 but will get lower performance. I use 93 because pumps in my area have 87-89-93 and I'm not **** enough to go 50/50 with 89 and 93. If I accidentally filled with 87, I wouldn't fret over it. I'd just take it easy until I was below half a tank and could re-fill it with 93.

You've discovered that you can't siphon gas from most cars these days. Take a look at the fuel tank, filler and vent system diagram in a shop manual. Gas thieves these days don't siphon. They punch a hole in the bottom of the tank.

Ken

 

Better fuel better performance !