HP Difference Between Reg and Premium? - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

woodj · 03-08-2012, 10:40 AM

Anyone ever figured out how much horsepower is lost by running regular fuel in an L99 or an LS3? I also own a 5.0 Mustang and the loss is only 10 horsepower (412hp vs. 402hp). With the price differential between regular and premium it might be worth changing over to save a few $$$ as gas gets more expensive. The 5, 20 fuse pull is easy enough to do later when switching back.

sasquash1984 · 03-08-2012, 10:41 AM

Don't get a tune mess ur motor up if ur running low octane, I believe the number your looking for is between 30-40 hp

90503 · 03-08-2012, 10:49 AM

Not sure about the hp thing...the way I understand it, premium is recommended...you can run regular...but will lose performance and if it knocks or doesn't run smooth on regular, premium needs to go in asap...

In relation to your question, I know that if you run premium, but are on the low octane setting, you're probably wasting your money...but not potentially harming the motor...not sure...good question....

VTXrider · 03-08-2012, 11:06 AM

Supposedly you also loose gas mileage but I'm suspicious of that assertion.

IndeedSS1 · 03-08-2012, 11:11 AM

How much is each additional degree of timing worth?
http://www.camaro5.com/forums/showpo...1&postcount=17

woodj · 03-08-2012, 11:12 AM

Quote:

Originally Posted by IndeedSS1

How much is each additional degree of timing worth?
http://www.camaro5.com/forums/showpo...1&postcount=17

Those charts are really pretty but do you have a simple answer by chance?

cab2g · 03-08-2012, 11:45 AM

I don't know the numbers, but they'd probably be on par with the Mustang. However, Ford has been specifically designing and testing the GT to run on both fuels and advertise this fact. GM on the other hand may not have tuned the ECM as precisely as Ford did and when your engine starts knocking, GM may have just used a "safety" timing table that will never knock, but also robs the engine of alot more power. But of course, this is all a guess. It may be less HP loss than the Mustang GT...

I personally would not mess with 87 octane because of all the headaches Camaro owners have had with it and the L99 TSB confirming the fact that the ECU actually does not reset when 93 octane is used again. I will continue to give GM the benefit of the doubt though and believe that my LS3 is not affected by the issue because it was not included in the TSB. And my dealer also put 89 in my car, I never did the fuse pull and a dyno shows that my car is on par with other LS3s on this site. But 89 octane may not have created any knocking before I filled up with 93 so maybe my ECU table was never switched... who knows...

woodj · 03-08-2012, 12:00 PM

Obviously if it can damage the engine or if the decrease in horsepower is dramatic (I once read 100 hp but I find that hard to believe) I wouldn't do it in the Camaro. For only a 10 hp decrease however, I think I'll just run regular in my Mustang.

CSM088 · 03-08-2012, 12:28 PM

I am also curious about this, more specifically if running 87 has any harmful effects on the LS3. I'd like to save some money on fuel by running 87 octane during the Winter when I can't even use the power.

Jeff_SS · 03-08-2012, 12:59 PM

The difference at the pump is like 2 dollars a tank. If that is stopping you after paying 30~40k for your Camaro, idk what to tell you.

90503 · 03-08-2012, 01:06 PM

Quote:

Originally Posted by CSM088

I am also curious about this, more specifically if running 87 has any harmful effects on the LS3. I'd like to save some money on fuel by running 87 octane during the Winter when I can't even use the power.

I would have thought about using regular if I was in slow traffic all the time or whatever (save a few bucks, no need for the power,etc)...but with that stupid fuse pull needed when going back to premium...not worth the hassle to me...

InfernoOrangeSS · 03-08-2012, 01:12 PM

Is there any easy way to know if you need to do the fuse pull? I have used 93+ ever since I have owned her, but don't know what the dealership put in there before I owned her. (I would assume the 87/89.)

YourBlindingBias · 03-08-2012, 01:14 PM

You shouldn't have to pull a fuse on your new car, did they have a fix for that on the newer models?

Sleez · 03-08-2012, 01:16 PM

i can't speak for the ss car, but in my v6, i keep very accurate records of mileage. i get a bit better mileage on super, so i started figuring the miles per dollar versus miles per gallon, and it comes out to almost identical. been getting right around 6 miles per dollar, at least until the next few tanks with the over $4/gal goes in to the calculations!!!

03-08-2012, 10:40 AM	#1
woodj Drives: 2SS/RS RJT Vert Join Date: Mar 2011 Location: Madison, AL Posts: 658 View My Garage	HP Difference Between Reg and Premium? Anyone ever figured out how much horsepower is lost by running regular fuel in an L99 or an LS3? I also own a 5.0 Mustang and the loss is only 10 horsepower (412hp vs. 402hp). With the price differential between regular and premium it might be worth changing over to save a few $$$ as gas gets more expensive. The 5, 20 fuse pull is easy enough to do later when switching back. __________________ K&N Typhoon CAI, Flowmaster Outlaw axle backs, Vertini 20" Wheels, Sparks Restorations SS Emblems, GM Wind Restrictor, Splash Guards

03-08-2012, 10:41 AM	#2
sasquash1984 502 RWHP N/A Drives: The yeti Join Date: May 2009 Location: Saginaw/ Ft Worth TX Posts: 3,085 View My Garage	Don't get a tune mess ur motor up if ur running low octane, I believe the number your looking for is between 30-40 hp __________________ factory motor factory trans, Gpi ss4 cam stock heads ported and milled, full exhaust, circle d 5c 4000 triple disk, 3:91 rear end with posi mod, cai, bmr derlin rear diff bushins, bmr derlin cradle bushins, bmr trailing arms, toe rods with bushings, and bmr anti extreme sway bar. Weld rt-s 17x5 fronts and 17X10 rears on mickey thompson et street r's

03-08-2012, 11:06 AM	#4
VTXrider Drives: 2010 RY 2SS/RS Join Date: Dec 2007 Location: Miami Posts: 817	Supposedly you also loose gas mileage but I'm suspicious of that assertion. __________________

03-08-2012, 11:11 AM	#5
IndeedSS1 Drives: 2010 Camaro SS LS3 Join Date: Sep 2010 Location: Eastern MO Posts: 3,786	How much is each additional degree of timing worth? http://www.camaro5.com/forums/showpo...1&postcount=17 __________________ She is only memory now.

03-08-2012, 11:45 AM	#7
cab2g love. my. car. Drives: 2011 2SS/RS Join Date: Jul 2009 Location: Chicago Posts: 3,372 View My Garage	I don't know the numbers, but they'd probably be on par with the Mustang. However, Ford has been specifically designing and testing the GT to run on both fuels and advertise this fact. GM on the other hand may not have tuned the ECM as precisely as Ford did and when your engine starts knocking, GM may have just used a "safety" timing table that will never knock, but also robs the engine of alot more power. But of course, this is all a guess. It may be less HP loss than the Mustang GT... I personally would not mess with 87 octane because of all the headaches Camaro owners have had with it and the L99 TSB confirming the fact that the ECU actually does not reset when 93 octane is used again. I will continue to give GM the benefit of the doubt though and believe that my LS3 is not affected by the issue because it was not included in the TSB. And my dealer also put 89 in my car, I never did the fuse pull and a dyno shows that my car is on par with other LS3s on this site. But 89 octane may not have created any knocking before I filled up with 93 so maybe my ECU table was never switched... who knows... __________________

03-08-2012, 10:49 AM	#3
90503 Drives: 2011 2SS/RS LS3 Join Date: Nov 2011 Location: Torrance Posts: 14,433	Not sure about the hp thing...the way I understand it, premium is recommended...you can run regular...but will lose performance and if it knocks or doesn't run smooth on regular, premium needs to go in asap... In relation to your question, I know that if you run premium, but are on the low octane setting, you're probably wasting your money...but not potentially harming the motor...not sure...good question....

03-08-2012, 12:00 PM	#8
woodj Drives: 2SS/RS RJT Vert Join Date: Mar 2011 Location: Madison, AL Posts: 658 View My Garage	Obviously if it can damage the engine or if the decrease in horsepower is dramatic (I once read 100 hp but I find that hard to believe) I wouldn't do it in the Camaro. For only a 10 hp decrease however, I think I'll just run regular in my Mustang. __________________ K&N Typhoon CAI, Flowmaster Outlaw axle backs, Vertini 20" Wheels, Sparks Restorations SS Emblems, GM Wind Restrictor, Splash Guards

03-08-2012, 12:28 PM	#9
CSM088 Drives: 1981 Z28 // 2010 1SS LS3 Join Date: Aug 2011 Location: Winnipeg, Canada Posts: 254	I am also curious about this, more specifically if running 87 has any harmful effects on the LS3. I'd like to save some money on fuel by running 87 octane during the Winter when I can't even use the power.

03-08-2012, 12:59 PM	#10
Jeff_SS "Cam Only" Drives: 2013 Camaro SS Join Date: Nov 2011 Location: Scottsdale, AZ Posts: 1,710 View My Garage	The difference at the pump is like 2 dollars a tank. If that is stopping you after paying 30~40k for your Camaro, idk what to tell you. __________________ 2013 AGM Camaro 2SS/RS M6 \| LSA Blower, 2.5" pulley, 10% lower, FIC1000's, Fore Innovations Twin Pump fuel system w/ Flex Fuel, CMS Custom Grind Cam, Kooks 1 7/8" headers w/ catless off-road pipes, NPP Exhaust, 3.91's, JLT ZL1 Intake, Prospeed Heat Exchanger \| Pfadt Suspension, 1LE Sway Bars \| DSS 1000hp axles \| Tuned by Ryne @ CMS E85: 734rwhp/636rwtq (mustang dyno)

03-08-2012, 01:14 PM	#13
YourBlindingBias Banned Drives: GT500/ZL1 Join Date: Jan 2012 Location: LA Posts: 336	You shouldn't have to pull a fuse on your new car, did they have a fix for that on the newer models?

03-08-2012, 01:16 PM	#14
Sleez Drives: 2010, 2LT, RS, 6M, ABM (#1893) SOLD Join Date: Mar 2011 Location: Willits, CA Posts: 1,437 View My Garage	i can't speak for the ss car, but in my v6, i keep very accurate records of mileage. i get a bit better mileage on super, so i started figuring the miles per dollar versus miles per gallon, and it comes out to almost identical. been getting right around 6 miles per dollar, at least until the next few tanks with the over $4/gal goes in to the calculations!!!