Quote:
Originally Posted by I-Hate-Hulse
Ethanol content in gas absolutely reduces fuel economy:
https://afdc.energy.gov/fuels/ethano...nt%20decreases).
In years past, certain retailers had higher levels of ethanol in their gas - usually the discount brands, so that lead to fuel economy differences.
However, government "clean fuel" regulations are now mandating ethanol content in fuels, so those differences are leveling out:
https://www.canada.ca/en/environment...ons/about.html
Certain blends of Premium from Retailers used to be ethanol free (Shell V-Power), so I could see how that lead to better fuel economy. Unfortunately regulations have made this a rare bird. |
This. I used to avoid Mowhawk/Husky or this reason but now it's unavoidable so I largely ignore the "this fuel contains 10% ethanol" sticker. I had an old Dodge 318 that the owners manual explicitly stated to not use ethanol blended gasoline. And this was the 90's, so it wasn't referring to E85, it meant any blend content.
Depending where you go, your gas is largely regionally sourced so it's all coming from the same refinery. It's all marketing.
As for premium, if you have a vehicle designed for premium, and you run regular, it'll r3tard the timing if it senses knocking which will lead to a reduction in power/efficiency. However, if you have a vehicle designed for regular, and you run premium, you likely won't see any performance benefits so you're just throwing money away.
We drive a vehicle with a Nissan VQ40 the "requires" premium however a previous Nissan vehicle with the same VQ40 didn't. The only difference I can find between the two engines that are 2 model years apart, is our current vehicle is an "LE" model and our previous wasn't. No changes to the cams, timing, performance specs, etc. The "luxury" vehicle requires premium gas and base model doesn't. We run regular gas in it and have seen no signs of knocking or performance drawbacks whatsoever.
We're also at a relative high elevation which helps. Not Colorado/Utah high where regular gas is 85 octane, but high enough than many "premium" vehicles can get away with regular or mid-grade gas without knocking or performance drawbacks.
Edit: can't talk about r3tarded timing apparently