Premium fuel and the R/T

MyNeonSaysHi · Post by **MyNeonSaysHi** » Tue Mar 20, 2012 2:51 am

Back on topic with premium fuel for a R/T or ACR. If I am not going to go WOT..reg fuel will be fine correct?

Post by **occasional demons** » Tue Mar 20, 2012 10:48 am

Regular (87 octane) fuel will be fine for all parameters. It just won't make the same power is all. The knock sensor feedback will basically de tune it, is all. I actually get better fuel mileage with 87 octane than 93. But it just doesn't have that little bit of extra umph, it does with higher octane. It isn't a huge difference, but it is noticeable.

If you don't mind slightly less fuel mileage, and want to boost the octane a little, use 2 or 3 gallons of E85 to a tank of 87 octane. The R/T PCM spark advance responds fairly well to it.

MyNeonSaysHi · Post by **MyNeonSaysHi** » Tue Mar 20, 2012 3:20 pm

occasional demons wrote:Regular (87 octane) fuel will be fine for all parameters. It just won't make the same power is all. The knock sensor feedback will basically de tune it, is all. I actually get better fuel mileage with 87 octane than 93. But it just doesn't have that little bit of extra umph, it does with higher octane. It isn't a huge difference, but it is noticeable.

If you don't mind slightly less fuel mileage, and want to boost the octane a little, use 2 or 3 gallons of E85 to a tank of 87 octane. The R/T PCM spark advance responds fairly well to it.

Are you running a complete R/T setup? Probably lower the gas mileage a bit putting that e85 in there..But it helps the octane since e85 is 104.

Post by **occasional demons** » Tue Mar 20, 2012 6:49 pm

Basically everything but the IM and 3.94 gears.

IM is a Ghetto Blaster with a 3 inch inlet, and 60 mm TB bolted on. If anything, it is more prone to detonation than a full out R/T. The only time that was a problem is when the knock sensor came unplugged.

'02 PCM, '02 cam.

MyNeonSaysHi · Post by **MyNeonSaysHi** » Thu Mar 22, 2012 12:27 am

Any other advantages running premium fuel? Cleaner burn? LEss deposits, (insert Shell V-Power statements etc etc.)

redneckmoparman · Post by **redneckmoparman** » Thu Mar 22, 2012 3:47 am

No thats all marketing hype higher octane burns slower allowing higher compression and more timing advance never run higher than reccomended it is a waste you will lose power and mileage running lower than reccomended will lose power also from retarded timing unless you can adjust timing(piggyback ms or 04/05 srt) or have changed compression use reccomended octane there are no added benifits of cleaners and crap thats all bullshit gas is gas just different burn rates

MyNeonSaysHi · Post by **MyNeonSaysHi** » Sat Mar 24, 2012 12:46 pm

Right on. Got 26MPG this past fill up. Had quite a few WOT pulls. Put some seafoam in the tank and filled it up with 87. Saved me $2.40 to go with 87 rather than 91.... Not going to do any WOT pulls and see what kind of MPG's I can get.

redneckmoparman · Post by **redneckmoparman** » Sun Mar 25, 2012 1:38 am

Man id be pissed if i got 26mpg im at 40 with playing around almost 45 if im good

Post by **occasional demons** » Sun Mar 25, 2012 8:58 pm

Well considering his R/T's overall gear ratio is 3.20:1 in fifth vs your 2.88:1, achieving 40 mpg might be a bit more difficult.

Post by **Canada** » Sun Mar 25, 2012 9:54 pm

And if you don't think the different additive packages each fuel company runs make a difference then you're an idiot. There is independent testing that shows fuels that are rate "Top Tier" promote much cleaner combustion chambers and valves which helps to keep the engine running properly and efficiently.

Also, Bill has a very valid point that the RT tranny and final drive makes it much harder to get higher mpg based on much higher rpm at cruising speeds.

MyNeonSaysHi · Post by **MyNeonSaysHi** » Tue Apr 03, 2012 12:13 am

Damn only got 27mpg on the last fill up with 87. No WOT runs. Didn't run it completely empty though. Filled up at 195 miles in.

Post by **Canada** » Tue Apr 03, 2012 7:43 am

Up here at least, one major difference between 87 / 89 / 91 is not only octane, but also ETHANOL content. They add between 10-15% in 87, 5-10% in 89 and 0% in 91, that will definitely effect your fuel economy.

stringburner · Post by **stringburner** » Tue Apr 03, 2012 7:11 pm

I average between 27 and 32 mpg in my '03 R/T on 87 octane. I've never once encountered detonation since I've been driving it in August of 2010, and I live in a mountainous/hilly location. it seems to run perfectly fine on low test. I've tried premium several times and like Bill I had a reduction in fuel economy.

trojmn · Post by **trojmn** » Tue Apr 03, 2012 9:14 pm

Canada wrote:Up here at least, one major difference between 87 / 89 / 91 is not only octane, but also ETHANOL content. They add between 10-15% in 87, 5-10% in 89 and 0% in 91, that will definitely effect your fuel economy.

When i was doing very consistant MPG testing with my old breeze I calculated that i would be better off paying up to ~29c MORE per Gal for E0 v E10. In the last few years im fairly certain all stations in my area are atleast E5 regardless of the grade, but ive only tested a few brands.

tro

RawkBunny · Post by **RawkBunny** » Wed Apr 04, 2012 1:24 pm

Gas prices are up over $5/gal in some parts down here, but I'll be damned if I put anything but premium in the car, if that's what it recommends.

MyNeonSaysHi · Post by **MyNeonSaysHi** » Wed Apr 04, 2012 11:35 pm

Canada wrote:Up here at least, one major difference between 87 / 89 / 91 is not only octane, but also ETHANOL content. They add between 10-15% in 87, 5-10% in 89 and 0% in 91, that will definitely effect your fuel economy.

Yeah I forgot about ethanol.. Up to 10% here so it probably is 10%. No wonder.

Fuzzyneon · Post by **Fuzzyneon** » Thu Jun 21, 2012 8:59 am

RawkBunny wrote:Gas prices are up over $5/gal in some parts down here, but I'll be damned if I put anything but premium in the car, if that's what it recommends.

this^ just put 93 (or 91) in it its not a big deal its not dollars more a gallon no reason not to its what it is reccomended

im sure if you wanna run regular you can but i wouldnt i want to get the most out of every car i drive