Gasoline Option Choices
07-04-2018, 08:36 PM
#1
Intermediate
Thread Starter
Gasoline Option Choices
I'm a fairly new owner of a '66 small block convertible. What is the better choice of fuel?
90 octane with NO ethanol or 93 octane with ethanol?
Thnak you in advance for your responses.
90 octane with NO ethanol or 93 octane with ethanol?
Thnak you in advance for your responses.
07-04-2018, 08:37 PM
#2
Team Owner
Member Since: Feb 2003
Location: Sitting in his Nowhere land Hanover Pa
Posts: 48,984
Received 6,928 Likes
on
4,774 Posts
2015 C2 of Year Finalist
what ever is more convenient for you. both will allow you to enjoy your car
07-04-2018, 09:18 PM
#3
I'd use the 90. Plenty of octane and no ethanol issues.
07-05-2018, 09:42 AM
#4
Race Director
Member Since: May 2000
Location: Redondo Beach USA
Posts: 12,487
Received 1,973 Likes
on
1,188 Posts
If it doesn't detonate on the 90 PON straight gasoline, use that. If it does detonate, then you'll need the 93, Bottom line is you need to test.
Duke
Duke
07-05-2018, 07:28 PM
#5
Race Director
Member Since: Apr 2015
Location: Fresno California
Posts: 17,503
Received 3,443 Likes
on
2,113 Posts
What C.T and Duke said. If your car will tolerate 90 octane straight gas, and is should, you'll get more power and better fuel economy. Alcohol likes to absorb water and has half the energy of gasoline.
07-06-2018, 09:03 AM
#7
Safety Car
last I looked there was non-ethanol 91 octane in Western NY
The following users liked this post:
jaybird92547 (07-06-2018)
07-06-2018, 11:27 AM
#9
Race Director
Member Since: Apr 2015
Location: Fresno California
Posts: 17,503
Received 3,443 Likes
on
2,113 Posts
07-06-2018, 12:38 PM
#11
Race Director
Member Since: Apr 2015
Location: Fresno California
Posts: 17,503
Received 3,443 Likes
on
2,113 Posts
Bill, it sounds like you use the lowest grade fuel that you can get that the engine will run on.. Kind of like the old-time farmers who started their tractors and model T's on gasoline and then switched over to kerosene when the engine got warm. Great for a 4:1 CR engine, not such a good idea for a performance V8. Yeah, your Corvette WILL run on 'panther ****', but not well, and not for long.
07-06-2018, 12:44 PM
#12
Le Mans Master
Bill, it sounds like you use the lowest grade fuel that you can get that the engine will run on.. Kind of like the old-time farmers who started their tractors and model T's on gasoline and then switched over to kerosene when the engine got warm. Great for a 4:1 CR engine, not such a good idea for a performance V8. Yeah, your Corvette WILL run on 'panther ****', but not well, and not for long.
Last edited by sstonebreaker; 07-06-2018 at 12:46 PM.
07-06-2018, 12:59 PM
#13
Race Director
Member Since: Jun 2006
Location: Inverness FL
Posts: 17,891
Received 727 Likes
on
621 Posts
St. Jude Donor '07
Bill, it sounds like you use the lowest grade fuel that you can get that the engine will run on.. Kind of like the old-time farmers who started their tractors and model T's on gasoline and then switched over to kerosene when the engine got warm. Great for a 4:1 CR engine, not such a good idea for a performance V8. Yeah, your Corvette WILL run on 'panther ****', but not well, and not for long.
I have become a believer in synthetic motor oil tho…
Bill
07-06-2018, 01:06 PM
#14
Team Owner
Member Since: Mar 2003
Location: Greenville, Indiana
Posts: 26,118
Received 1,843 Likes
on
1,398 Posts
I would speculate that almost any gasoline you get out of a pump today is a far better quality gasoline for your engine than any pump gas you could buy 50 years ago. And that includes E 10. All things considered.
07-06-2018, 01:14 PM
#15
Race Director
Member Since: Jun 2006
Location: Inverness FL
Posts: 17,891
Received 727 Likes
on
621 Posts
St. Jude Donor '07
I installed the ZZ4 in December 2010 and have put 19790 miles on it since then, always with 87 octane, mostly E10. drove it 10K+ miles out west and up to elevations over 11K foot with no apparent problems. so, i'm happy...
Bill
07-06-2018, 01:20 PM
#16
Le Mans Master
07-06-2018, 01:24 PM
#17
Race Director
Member Since: Jun 2006
Location: Inverness FL
Posts: 17,891
Received 727 Likes
on
621 Posts
St. Jude Donor '07
Not me. More than once, when checking out a barn find with friends, we've been able to start a car that's been sitting for 40 or 50 years with the gas that was in its tank; but one that's been sitting with a tank full of E-10, no way. The E-10 has absorbed water and if you're lucky all you have to do is drop the tank and swap out the fuel pump. If it's a metal tank, you usually have to boil out the rust if not replace the entire tank. And if it's a carbureted engine, you usually have to rebuild the carb as well.
Bill
The following users liked this post:
wmf62 (07-06-2018)
07-06-2018, 02:01 PM
#19
Team Owner
Member Since: Mar 2003
Location: Greenville, Indiana
Posts: 26,118
Received 1,843 Likes
on
1,398 Posts
Far better quality for your engine.............All things considered.
Starting a car up on 15-50 year old gas is not only a bad idea, it's not an indicator of the type quality I was talking about.
One little tidbit I'll throw out is, you don't see engine bearings eaten up by sulphur in the crankcase, unlike what you used to see when you tore down an engine. Where do you suppose that sulphur came from?
You don't see large carbon deposits anymore like you used to see either.
I'd say more but I'm no chemist and I'd quickly get in over my head.
07-06-2018, 02:09 PM
#20
Race Director
Member Since: Jun 2006
Location: Inverness FL
Posts: 17,891
Received 727 Likes
on
621 Posts
St. Jude Donor '07
I'm not sure if you're following what I posted.
Far better quality for your engine.............All things considered.
Starting a car up on 15-50 year old gas is not only a bad idea, it's not an indicator of the type quality I was talking about.
One little tidbit I'll throw out is, you don't see engine bearings eaten up by sulphur in the crankcase, unlike what you used to see when you tore down an engine. Where do you suppose that sulphur came from?
You don't see large carbon deposits anymore like you used to see either.
I'd say more but I'm no chemist and I'd quickly get in over my head.
Far better quality for your engine.............All things considered.
Starting a car up on 15-50 year old gas is not only a bad idea, it's not an indicator of the type quality I was talking about.
One little tidbit I'll throw out is, you don't see engine bearings eaten up by sulphur in the crankcase, unlike what you used to see when you tore down an engine. Where do you suppose that sulphur came from?
You don't see large carbon deposits anymore like you used to see either.
I'd say more but I'm no chemist and I'd quickly get in over my head.
, on all counts.... 
Bill