Hmmm, I've found the opposite to be true. A car tuned to the edge will exhibit a 1% decrease in power for every 10*F increase in ambient air temperature, on a dyno. It ony goes to reason, why do you think drag racers prefer racing on uber cold days?

 

I don't have a MAP sensor to log boost yet. I would say looking at my gauge though that boost was a little LOWER if anything... strange I know but it deffinatly wasn't higher.

 

Interesting... I have heard/read the opposit.

 

I also heard 76 was most consistant, and best knock deterrant. Also i believe Vishnu tuned a car back to back on a tank of Chevron, then on a tank of 76, and the 76 netted 7 awhp more, i think.

Still i only put Chevron in my car unless i'm heading to the track. Don't ask why...

 

umm WAWA's buy their gas directly from Sunoco. http://abclocal.go.com/wpvi/story?se...mer&id=3358152 read towards the bottom.

 

Another thing to consider is that if you go to a station that uses one hose for all grades then you may be getting up to 2 1/2 gallons of another grade. Only use stations that have different hoses for all grades. I learned this lesson with my bikes where the tank is much smaller and it is very noticable. I hope this helps.

 

This was what I was thinking too.

Hotter day, run richer so less knock. colder days, more dense air/fuel mixture, you run lean you get more kncoks.

And i'm sure it's not knock knock, and it's just the knock voltage acting up a little bit more. I could be wrong.

it really depends on the how different gas companies rate their octane levels.

Their Research octane level maybe way too high for what it really is, so you maybe end up getting something like 91 octane instead of 93 octane at some of the smaller gas companies.

refinement is an issue, but the smaller gas companies usually get their gas from bigger companies like BP, Exxon, etc, but just less detergent and additives.

 

i try to run BP only.

 

A little info. I like BP as well btw. Ultimately they make my oil anyway.

http://www.caranddriver.com/columns/...y-webster.html

http://www.toptiergas.com/

 

I think the station itself is also a large variance. Maybe not all of one type of station are equal to another station of the same brand.

I do know that the formulation of race gas Sunoco provides for our race team varies widely from one area of the country to another. According to the rep it could be anywere from 5-30% tolulene. That is a huge difference. I can't imagine any company's pump gas being identical from sea to shinning sea.

 

Sunoco and Mobil 4life

 

This is a great point especially since we have small tanks in our cars, but theres another thing that hasn't been mentioned yet...

I get this info straight from the horses mouth(fuel truck driver) about what happens with fuel deliveries. Now I forget the exact reason because it was tough to follow but basically they try to return from a trip with an empty truck. Lets say they've topped off the stations 87 tank and have a little left in the truck. Rather than keeping it and returning with it, they get rid of it where ever they might have room(93 tanks). I've also been noticing this lately My car was tuned by Sean Ivey a while ago and it ran great even on the 90 sumthin degree day he tuned it. I get home and it kinda starts hiccupin on me off and on, no real atmospheric changes, but i started thinkin about fuel lately. There is definately a change from station to station. I've been having good luck with mobil so far...

 

My buddy works at the BP refinery here in Southern California and they refine oil from many many different companies and pipe it off to each corporation using the same pipes and fuel. The differences you'll find after that is the additives companies put in their fuel.

91 octane BP is the same 91 octane you'll find in Arco Gasoline except BP puts good additives in it.

(all second hand knowledge from a guy who is a pipeline controller)

 

I only run 76 in my car. Either 91 or 100 if I'm feeling frisky.

 

Mobil 93 octane for the last year....works good for me.