Elevation also affects the gas. Higher altitude places will be able to use 85 octane just fine.
Thanks, Jason. Good to know as Utah has 85 for regular. I've never used anything but 85 in my Outback with no issues.
Elevation also affects the gas. Higher altitude places will be able to use 85 octane just fine.
This is absolutely untrue. If the ecu cannot compensate and was designed for 87 running 91 will only cause you to spend more money. 87 has more energy than 91 the benefit in 91 is it burns slower letting you run more timing which the ecu can be tuned to get more power from.Having owned many turbo cars and even some that say you can use regular unleaded, do your car a favor and just run premium. Turbo vehicles will always run better with higher octane regardless if the ECU can compensate.
Well, I've not known the Subie ECUs on the FAs to not adjust based on fuel - it's part of how they avoid knock.This is absolutely untrue. If the ecu cannot compensate and was designed for 87 running 91 will only cause you to spend more money. 87 has more energy than 91 the benefit in 91 is it burns slower letting you run more timing which the ecu can be tuned to get more power from.
Top tier fuel will be fine without going to 93 octane. Just a waste of money, since Subaru explicitly says you don't need it for the car to run fine.Well, I've not known the Subie ECUs on the FAs to not adjust based on fuel - it's part of how they avoid knock.
Regardless, going to 93 sees additional benefits, such as all the fancy detergents that aren't in the other octane tiers.
"octane tiers" should have been "octane levels" to avoid confusion, since "Top Tiers" isn't the same thing - it's a license rating that indicates gas quality and detergent/additives inclusion. (link: https://www.toptiergas.com/). Sorry if I was confusing.Top tier fuel will be fine without going to 93 octane. Just a waste of money, since Subaru explicitly says you don't need it for the car to run fine.
In one test, Shell's 93 octane has virtually twice the detergents of its 87 octane. Mobil has a little bit more in their 93 than their 87. BP has over 50% more detergent in their 93 than in their 87 octane. Pilot and Marathon have 65% more detergent in their 93 octane. That trend continues across most brands with very few having similar amounts in 87 and 93 octanes."Engineered with triple-action protection for optimal engine performance. Unsurpassed protection against gunk. Unbeatable protection against corrosion. Our best protection against wear."
This engine is based off the FXT FA20DIT. The FA20 FXT also states 87 can be used at the expense of performance, gas mileage and possible engine knocking. I can't understand why anyone would spend this much money on their Ascent then cheap out on the gas. It's your vehicle and you can use whatever you want though.This is absolutely untrue. If the ecu cannot compensate and was designed for 87 running 91 will only cause you to spend more money. 87 has more energy than 91 the benefit in 91 is it burns slower letting you run more timing which the ecu can be tuned to get more power from.
Ok, so... based on the list from the news article, if you go with the NON Top Tier brands on the list, and multiply by 5, that's 26mg per ml, which beats all the other tested brands except Shell at 31mg. Shell is the lowest 87 octane top tier and the lowest detergent level of the ones tested (ironic, since they're the highest detergent level as well, when you look at their 93). 16.2mg times 5 would be 81mg... hmmm... maybe I need to renew my Costco membership... I can get 87 octane and all the detergent I could ever want.I'd be curious to see what the Costco Gasoline comes in at. They advertise all over that they have 5 times (5x) the number of detergents compared to whatever "normal" Top Tier fuel is.
But, like you pointed out, not sure if that's referencing 87 or 93. They only offer 87 and 93 at my local warehouse.
Also, with these engines being DI - you should always put in top tier fuel. Always.
The problem is that Shell 93 blows away every competitor tested - by a LOT. They also blow away their 87 octane. Costco makes a claim that would mean their 87 is at least near equal to Shell's 93.Since higher octane gasoline is not required, buy regular and place a priority on getting a Top Tier gasoline that has additives.
I’ve emailed Costco for clarification. I'll try to get a more exact amount, and whether or not the 87/93 is different.The problem is that Shell 93 blows away every competitor tested - by a LOT. They also blow away their 87 octane. Costco makes a claim that would mean their 87 is at least near equal to Shell's 93.Since higher octane gasoline is not required, buy regular and place a priority on getting a Top Tier gasoline that has additives.
So, maybe Costco 87 (or any octane) is the way to go?
The only definite "known element" is that Shell's 93 is far superior to anything tested.
Costco is Top Tier, I try to fill up at Costco most of the time and they have the Top Tier logo on the pumps. It is also right on their website. https://www.costco.com/gasoline.htmlI'd be curious to see what the Costco Gasoline comes in at. They advertise all over that they have 5 times (5x) the number of detergents compared to whatever "normal" Top Tier fuel is.
But, like you pointed out, not sure if that's referencing 87 or 93. They only offer 87 and 93 at my local warehouse.
Also, with these engines being DI - you should always put in top tier fuel. Always.
We know it's Top Tier, but that doesn't necessarily mean it's the best. :tango_face_wink:Costco is Top Tier, I try to fill up at Costco most of the time and they have the Top Tier logo on the pumps. It is also right on their website. https://www.costco.com/gasoline.htmlI'd be curious to see what the Costco Gasoline comes in at. They advertise all over that they have 5 times (5x) the number of detergents compared to whatever "normal" Top Tier fuel is.
But, like you pointed out, not sure if that's referencing 87 or 93. They only offer 87 and 93 at my local warehouse.
Also, with these engines being DI - you should always put in top tier fuel. Always.
This engine is based off the FXT FA20DIT. The FA20 FXT also states 87 can be used at the expense of performance, gas mileage and possible engine knocking. I can't understand why anyone would spend this much money on their Ascent then cheap out on the gas. It's your vehicle and you can use whatever you want though.
Because it was designed to run it. By engineers. The engineers who built the engine.
Just because the motor is based off another motor doesn't mean anything on its own. There are so many little things that could have been changed that would have an effect on whether or not you need the anti-pinging provided by 93. Because that is what it comes down to, ping (or knock). If they lowered the compression, or in some other way compensated for it, then voila no need for 93.
The detergent thing may be a valid point, idk, but I would bet in a few years there are going to be a lot of 200k mile Ascents out there that have never had a lick of premium through them. Also, you could probably throw some additive in every few tanks to simulate the benefits of the detergent you would miss running 87.