Premium vs Regular MPG: A 34-Tank Test

cvx5832LC

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Like most of you, I've been curious about why the T24A-FTS is rated at the same horsepower when spec'd for Premium on the LC vs Regular for the Tacoma. Since I didn't have access to a dyno or a Tacoma I could run on Premium vs Regular and comparing that data to my LC, the most I could do was to look at my fuelly log.

I am not trying to convince you to use one or the other, nor am I promoting bashing the other guy for using one or the other. We're all big boys and girls here and we can make these decisions on our own. That said, a good discussion, to a certain degree, allows us to make said decisions.

Some things to note:
  • California opened to winter blend gasoline November 1st. This puts the entirety of the "Regular" portion of this test using winter blend, and some (4 of 17) of the "Premium" portion using the same. While the shitty winter stuff is cheaper to produce, I'll let you draw your own conclusions as to when it would have been available at the pump
  • I used my local Costco whenever I could
  • I could not (objectively) account for the cooler weather this time of year
  • The spikes in MPG, believe it or not, is when I encountered traffic on my 92-mile round trip commute with my son
  • The LC is primarily a people hauler. If I am alone I take 2 doors or 2 wheels
  • This test started ~9k miles on the odo, so the motor is broken-in
With that, here's what I got during this 34-tank journey:

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In practical terms, the reduced MPG (but lower per gallon cost) nets me about $400 a year on my 25k-mi/year usage of this vehicle. This is based on a $0.38 variance between Premium vs Regular. I included other mileage metrics for the group:

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In terms of performance, I have not noticed a difference in my usage. For reference, we have 4 other cars spec'd for Premium. A BMW F10 and E46, a Subaru ZD8 and Mercedes W204. When I use Regular on those vehicles, the difference is obvious. Particularly when merging on freeways at full bore, or trying to accelerate at a high gear. Not on the LC. If there's a difference, my butt-dyno doesn't pick up on it.

Closing thoughts:
  • I will revisit this next year so I can chart a YoY and a more apples-to-apples comparison
  • If you can afford an LC, the ~$250 saved for the average user (15k miles) is probably not worth it
  • I will continue to use Regular in my LC in the interest of long-term testing. That and it pays for all of my wife's and son's online subscriptions.
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GREAT review/data on a very controversial subject! Question, did you notice any engine pinging or misfiring?

The fuel filler door now indicates 87 octane or higher. This differs from what others have posted.
 
GREAT review/data on a very controversial subject! Question, did you notice any engine pinging or misfiring?
I did not. For reference, my FA24'd Subaru is notorious for LSPI, and would ping if you looked at the clutch wrong. So I know what it would sound like. I deliberately listen out for it, so if it's there, it's beyond my detection.
 
Stillen just released a YouTube video on dyno testing a '24 Taco turbo on 87 vs 91 octane pump gas if you're curious. Summary: -20whp
In for a link. Since the Taco is spec'd for Regular, does the report say it performs 20hp better with Premium?
 
The fuel filler door now indicates 87 octane or higher. This differs from what others have posted.
Missed this comment. That's my add. A reminder since all of our vehicles take Premium.
 
In for a link. Since the Taco is spec'd for Regular, does the report say it performs 20hp better with Premium?

 
It was unclear to me if the tests were conducted with modified exhaust, thus taking advantage of the higher octane.
 
The “87 or higher octane” sticker is what Toyota should have put on the 2024. Instead they put “premium fuel only, no diesel “ . That led a lot of dunces to believe that 93 octane HAD to be used or the lc would not run. Where I fuel up they have regular, nitro, and nitro +. No “premium “. They do have diesel though and since the 2025 does not have a “no diesel “ sticker…
 
The “87 or higher octane” sticker is what Toyota should have put on the 2024. Instead they put “premium fuel only, no diesel “ . That led a lot of dunces to believe that 93 octane HAD to be used or the lc would not run. Where I fuel up they have regular, nitro, and nitro +. No “premium “. They do have diesel though and since the 2025 does not have a “no diesel “ sticker…
I am just happy Toyota clarified the issue on the 2025's! It sure resulted in many heated comments on this forum...
 
I am just happy Toyota clarified the issue on the 2025's! It sure resulted in many heated comments on this forum...
It creates a new controversy however. How come the 2025 can run on diesel but the 2024 can’t? Are they tuned differently?
 
GREAT review/data on a very controversial subject! Question, did you notice any engine pinging or misfiring?

The fuel filler door now indicates 87 octane or higher. This differs from what others have posted.
If true I think it confirms the premium requirement was always BS.
 
The “87 or higher octane” sticker is what Toyota should have put on the 2024. Instead they put “premium fuel only, no diesel “ . That led a lot of dunces to believe that 93 octane HAD to be used or the lc would not run. Where I fuel up they have regular, nitro, and nitro +. No “premium “. They do have diesel though and since the 2025 does not have a “no diesel “ sticker…
Pretty sure the ‘24 manual specifically states 91 octane minumum
 
Just a comment on the premium vs regular cost chart posted at the top of this thread………

In my area, current best prices are around $4.00 for premium, $3.50 for mid-grade, and $3.00 for regular. I believe all are E10.

So there is about a $1.00 difference between premium and regular, making the annual cost calculation somewhat different.
 
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I think the “premium “ requirement was misinterpreted by many to mean the highest possible octane available. When it probably meant use gasoline and not diesel.
I don’t see how that could possibly be the case. The manual specifies 91 octane. Premium has nothing to do with gas versus diesel
 
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