Someone recently told me that at higher altitudes it isn't necesary to run 91 octane(which is premium in colorado). Now I don't know if this is true or not. Just wanted to get some input. Sorry if this is a repost!
Thanks

 

Well at a higher altitude there is less oxygen to oxidize the fuel? Higher octane would give you better gas mileage but in a higher altitude with "thinner" air there would be less wind resistance also giving you better gas mileage. It still doesn't account for the affect on the engine though. Just my bio/chem brain thinking out loud.

 

My guess is the Manifold Air Pressure sensor would detect the lower air pressure and dump less fuel for combustion. But the issue is when the car is in VTEC, it has almost the same power as it would in a lower altitude, so you would have to be very careful running lower octane to avoid knock. My is just to use 91

 

Compression in the cylinder is still 11:1.

91 is to combat compression detonation and/or knock.

Use the 91.

 

Cool thanks for ur input guys I really appreciate it. I've been using 91 since I bought it and don't feel like risking any noises lol. Its worth the 2.09/gallon. Thanks again!

 

2.09!!! you better be running 91 at that price!!!!
Do a seafoam treatment to the intake manifold and some good gas cleaner thru the tank
Make that thing run great at altitude

 

Yeah gas prices are the same in Michigan 2.09 for 93 octane.

My last car required premium too, really its only a 2-3$ difference in a full tank of gas @ 10-20 cents more a gallon.

I did notice when traveling throughout higher altitude regions they have lower octane fuels, why is that? Something to do with oxygen density?

 

some areas get 93 instead of 91
Its about the altitude and other factors
run the TL on 91 or 93 if thats what they sell where you live
If type S- dont even think about 87 octane!!

 

In Colorado they sell 85 octane rather than 87 (at least they did last time I was out there). I did a bit of a double-take at the pump and then proceeded to use the 85 since I was driving a rental car.

Sunoco stations here generally carry both 91 and 93. 91 is usually 2¢ a gallon cheaper, and I've had no problems running the TL on that stuff. I won't go out of my way to find a station that carries it, though, since doing that would waste more than the 25 to 30¢ savings.

 

no idea but ill tell u in canada for 2 months i had big problems pumping 91.... throwing cels like no ones business.... so i finally got back to the US plugged it in and they said bad gas. they told me i should pumped lower than 91. i didnt ask questions i just said ok peace out.

 

What does the seafoam do? Not familiar with it.

 

it cleans the carbon out of the engine and desposits off of the injectors and removes them from the fuel system.

 

use 91+ why would you even wanna risk the knocking, i use 93 anyways it works the best for me, i notice the big differences.

 

Ive used 89 from day 1 since i bought the car. But for a month every week i put in ultimate cuz it was cheap. Lmao u don't need 91 u can use 89.

 

You guys gotta do the 94

 

I used to live in SE Washington and took a road trip to Vancouver BC, got pulled over at customs and they tore apart my car! hahaha i couldn't believe it.

At the gas station i couldn't believe the octane was higher! and by the liter which confused me. Why do canadians stock higher octanes? Is it an elevation thing?

 

The Sunocos here used to carry 94, but they phased it out because of MTBE regulations and now they have 91 and 93. Too bad, my brother's 1974 Beetle loved that stuff. I last used 94 at a Petro-Canada station in Ottawa a few years back (odd thing was, the Petro-Canada in Sydney, Nova Scotia, didn't carry 94 this summer). After filling up with the 94 I then drove back to Virginia, had to stop once in Pennsylvania to refuel and I averaged 30 mpg with an average speed of 70 mph. No idea whether the fuel played any part in that; I rather doubt it.

 

I found there really wasn't any difference between pumping 94 and 91 up here. I've had my 05 TL for about 2 months and have been meticulously tracking the mileage. There was absolutely no variation in mileage, only 94 would empty my wallet a bit faster. Not actually sure why we stock 94 up here. People seem to like pumping 94 into their civic's, accord's, etc. Not really sure what benefit it has...

Not surprised about customs, I usually have little to no problems going southbound, northbound however is another story....

 

Hey, since you're in Burnaby, how much mileage do you get?

I still haven't driven it enough to get an idea of my average yet. My first tank of 94 sucked, barely hit 400kms if that. I figured the guy before me used crap gas. Second tank of 94 I dumped a can of seafoam in and I was getting up to 500+kms. On my third tank of 94 now and initially the trip computer guestimated 565kms! but now it's down to about 470kms. Will see where it settles out.

I put 94 simply because it's cleaner burning.

I'm going for my first oil change and will put some seafoam in the oil on the way to the dealership. After I'll do the seafoam intake treatment.