# FJ Cruiser Gas Octane Requirements

**URL:** <https://community.cartalk.com/t/fj-cruiser-gas-octane-requirements/63203>\
**Category:** Maintenance/Repairs\
**Tags:** toyota\
**Created:** [March 31, 2011, 2:03am UTC](https://community.cartalk.com/t/fj-cruiser-gas-octane-requirements/63203 "2011-03-31T02:03:00Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![Tom\_Cruiser](https://avatars.discourse-cdn.com/v4/letter/t/bbe5ce/32.png) [@Tom\_Cruiser](https://community.cartalk.com/u/Tom_Cruiser)\
**Post date:** [March 31, 2011, 2:03am UTC](https://community.cartalk.com/t/fj-cruiser-gas-octane-requirements/63203/1 "2011-03-31T02:03:00Z")

</div>

Why does my FJ Cruiser specify premium gas only? I don’t tow and 90% is highway. I’ve tried regular and don’t notice knocking or reduced mileage. What’s the deal?

---

<div class="post-metadata">

**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\
**Post date:** [March 31, 2011, 2:05am UTC](https://community.cartalk.com/t/fj-cruiser-gas-octane-requirements/63203/2 "2011-03-31T02:05:24Z")

</div>

Please let us know the exact wording from the owners manual.

---

<div class="post-metadata">

**Author:** ![Joseph\_E\_Meehan](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/joseph_e_meehan/32/21_2.png) [@Joseph\_E\_Meehan](https://community.cartalk.com/u/Joseph_E_Meehan)\
**Post date:** [March 31, 2011, 10:32am UTC](https://community.cartalk.com/t/fj-cruiser-gas-octane-requirements/63203/3 "2011-03-31T10:32:12Z")

</div>

If it says high octane only, then that is what the engine is designed for. Using regular can shorten the life of your engine and reduce the mileage and power.

First octane is a measure of how fast the fuel will burn. High octane burns slower, which allows the engine to be designed more power. Using lower octane fuel can cause reduced power, lower mileage and possible damage to your engine.

You may not notice the knocking, but in the long run it likely will cost you more.

```
texases is correct. Please tell us exactly what the owner's manual or the sticker on the car says about octane.
```

---

<div class="post-metadata">

**Author:** ![MikeInNH](https://avatars.discourse-cdn.com/v4/letter/m/a587f6/32.png) [@MikeInNH](https://community.cartalk.com/u/MikeInNH)\
**Post date:** [March 31, 2011, 6:33pm UTC](https://community.cartalk.com/t/fj-cruiser-gas-octane-requirements/63203/4 "2011-03-31T18:33:18Z")

</div>

You don’t hear any knocking because the knock sensor is doing it’s job. If it wasn’t you might hear knocking and worse case it could destroy your engine. By using regular…the engine management system will retard the timing if knocking is detected. This will reduce power AND gas mileage. You won’t be saving any money by using regular…and you run the risk (although very low) of destroying the engine.