# 2017 Toyota 4Runner - Premium fuel **URL:** \ **Category:** General Discussion\ **Tags:** toyota\ **Created:** [November 11, 2018, 4:41pm UTC](https://community.cartalk.com/t/2017-toyota-4runner-premium-fuel/128632 "2018-11-11T16:41:19Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![ClarkTuck](https://avatars.discourse-cdn.com/v4/letter/c/b3f665/32.png) [@ClarkTuck](https://community.cartalk.com/u/ClarkTuck)\ **Post date:** [November 11, 2018, 4:41pm UTC](https://community.cartalk.com/t/2017-toyota-4runner-premium-fuel/128632/1 "2018-11-11T16:41:19Z")
Ray, It seems to me that most newer cars recommend 91 octane fuel. I think it is mainly because high octane fuel increases fuel mileage slightly. But high octane fuel costs a lot more than the small increase in mileage. I think that as long as an engine does not make strange sounds with regular octane fuel it is not doing any harm to the engine. Please let me know what you think. Clark ---
**Author:** ![Mustangman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mustangman/32/44130_2.png) [@Mustangman](https://community.cartalk.com/u/Mustangman)\ **Post date:** [November 11, 2018, 7:18pm UTC](https://community.cartalk.com/t/2017-toyota-4runner-premium-fuel/128632/2 "2018-11-11T19:18:47Z")
> [@ClarkTuck](#): > > I think it is mainly because high octane fuel increases fuel mileage slightly. You are incorrect. (I am not Ray, BTW) The octane in itself does not increase MPG’s. Only if the engine is tuned to make use of the higher octane, does the MPG increase. > [@ClarkTuck](#): > > I think that as long as an engine does not make strange sounds with regular octane fuel it is not doing any harm to the engine You are wrong there, too. Detonation or pre-ignition can exist such that you cannot hear it and there for cause some damage to the engine. As we tell posters here that want to justify putting 87 octane fuel in cars that REQUIRE 91 or 93 octane fuel; Don’t do that, use the fuel required by the manufacturer. If it says 91 octane preferred, then the car is configured to run best on 91 but you can use 87. If the manufacturer say 91 is REQUIRED, use that or damage may occur. ---
**Author:** ![ClarkTuck](https://avatars.discourse-cdn.com/v4/letter/c/b3f665/32.png) [@ClarkTuck](https://community.cartalk.com/u/ClarkTuck)\ **Post date:** [November 12, 2018, 2:16am UTC](https://community.cartalk.com/t/2017-toyota-4runner-premium-fuel/128632/3 "2018-11-12T02:16:32Z")
How do I know that you are someone that knows what they are talking about or just someone that has an opinion? ---
**Author:** ![VOLVO-V70](https://avatars.discourse-cdn.com/v4/letter/v/8e8cbc/32.png) [@VOLVO-V70](https://community.cartalk.com/u/VOLVO-V70)\ **Post date:** [November 12, 2018, 2:28am UTC](https://community.cartalk.com/t/2017-toyota-4runner-premium-fuel/128632/4 "2018-11-12T02:28:05Z")
Ray doesn’t ever respond here as far as I know. I can vouch for Mr. Mustang as someone who does know what he is talking about. You are welcome to your ideas but you are a little off base. Most vehicles sold are designed to use regular unleaded 87 fuel . But if it requires premium then that is what should be done. ---
**Author:** ![Purebred](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/purebred/32/46796_2.png) [@Purebred](https://community.cartalk.com/u/Purebred)\ **Post date:** [November 12, 2018, 3:45am UTC](https://community.cartalk.com/t/2017-toyota-4runner-premium-fuel/128632/5 "2018-11-12T03:45:04Z")
Do you think Toyota does not know what they are talking about either? ---
**Author:** ![Mustangman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mustangman/32/44130_2.png) [@Mustangman](https://community.cartalk.com/u/Mustangman)\ **Post date:** [November 12, 2018, 2:18pm UTC](https://community.cartalk.com/t/2017-toyota-4runner-premium-fuel/128632/6 "2018-11-12T14:18:14Z")
You don’t. But you posted on the CarTalk Forum looking for answers, I obliged and reiterated what every owners manual says about fuel octane. I just answered your “I think” theories. If you don’t believe my answer, fine, do your own research. It might be fun. I’d suggest reading “Internal Combustion Engines and Air Pollution” by Edward F. Obert for starters. ---
**Author:** ![GorehamJ](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/gorehamj/32/24103_2.png) [@GorehamJ](https://community.cartalk.com/u/GorehamJ)\ **Post date:** [November 12, 2018, 9:53pm UTC](https://community.cartalk.com/t/2017-toyota-4runner-premium-fuel/128632/7 "2018-11-12T21:53:26Z")
I like the topic. I disagree that “Most new cars recommend 91 octane.” My estimation would be that maybe 20% of the cars sold in America come with this recommendation. Not a single top selling car model in the U.S. has that recommendation that I know of. Rogue, CR-V, RAV4, Camry, Accord, Civic, Corolla, Altima, Sentra, Model 3, that is pretty much the list of top sellers accounting for a massive part of the market. Throw in the F-150 if you like. None suggest or hint at 91 octane that I am aware of. There are premium and luxury models that do recommend the pricey stuff, and I think the reasons are 1) Bragging rights for a handful of HP 2) Fuel economy as you suggest. ---
**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\ **Post date:** [November 12, 2018, 10:07pm UTC](https://community.cartalk.com/t/2017-toyota-4runner-premium-fuel/128632/8 "2018-11-12T22:07:41Z")
> [@ClarkTuck](#): > > It seems to me that most newer cars recommend 91 octane fuel That is incorrect. > [@ClarkTuck](#): > > I think that as long as an engine does not make strange sounds with regular octane fuel it is not doing any harm to the engine. That is also incorrect. > [@ClarkTuck](#): > > Please let me know what you think. I think that you need to do a considerable amount of research on this topic, rather than relying on your assumptions. 🤔 ---
**Author:** ![jtsanders](https://avatars.discourse-cdn.com/v4/letter/j/c2a13f/32.png) [@jtsanders](https://community.cartalk.com/u/jtsanders)\ **Post date:** [November 12, 2018, 10:22pm UTC](https://community.cartalk.com/t/2017-toyota-4runner-premium-fuel/128632/9 "2018-11-12T22:22:13Z")
On page 474 of the 2017 4Runner owner’s manual, Toyota says to use 87 octane or higher (91 research octane). Note that there are two numbers. Research octane (RON) is used in Europe, while the Anti-knock index (AKI) is used in the US and Canada. There is a third index called Motor Octane Number (MON). AKI is the average of RON and MON. If you are in North America, use 87 AKI. If in Europe, use RON. Given the information in the owner’s manual, you can calculate the MON if you want to. ---
**Author:** ![SteveCBT](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/stevecbt/32/3192_2.png) [@SteveCBT](https://community.cartalk.com/u/SteveCBT)\ **Post date:** [November 12, 2018, 11:40pm UTC](https://community.cartalk.com/t/2017-toyota-4runner-premium-fuel/128632/10 "2018-11-12T23:40:55Z")
@ClarkTuck , you came here asking for an opinion and unfortunately for you making a statement about mileage that is incorrect. Then you have the audacity to challenge one of our respected members when they give you solid, expert, free advice. You might want to sit back a bit and see what the other replies are and you will see that @Mustangman was right on with his answer. ---
**Author:** ![oldtimer-11](https://avatars.discourse-cdn.com/v4/letter/o/e79b87/32.png) [@oldtimer-11](https://community.cartalk.com/u/oldtimer-11)\ **Post date:** [November 13, 2018, 3:19am UTC](https://community.cartalk.com/t/2017-toyota-4runner-premium-fuel/128632/11 "2018-11-13T03:19:37Z")
If you receive an incorrect answer on this forum, please take advantage of our double your money back guarantee. ---
**Author:** ![Nevada\_545](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nevada_545/32/41232_2.png) [@Nevada\_545](https://community.cartalk.com/u/Nevada_545)\ **Post date:** [November 13, 2018, 7:44am UTC](https://community.cartalk.com/t/2017-toyota-4runner-premium-fuel/128632/12 "2018-11-13T07:44:20Z")
> [@ClarkTuck](#): > > I think that as long as an engine does not make strange sounds with regular octane fuel it is not doing any harm to the engine. This is what the owners manual states about using 87 octane fuel; _You may occasionally notice light knocking for a short time while accelerating_ _or driving uphill. This is normal and there is no need for concern._ I wouldn’t be concerned with octane with modern vehicles, they all have knock sensors that are necessary to control the oxides of nitrogen that might exceed federal standards if pre-ignition were allowed to occur. ---
**Author:** ![FoDaddy](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/fodaddy/32/717_2.png) [@FoDaddy](https://community.cartalk.com/u/FoDaddy)\ **Post date:** [November 13, 2018, 1:50pm UTC](https://community.cartalk.com/t/2017-toyota-4runner-premium-fuel/128632/13 "2018-11-13T13:50:35Z")
> [@ClarkTuck](#): > > It seems to me that most newer cars recommend 91 octane fuel. Some do, some don’t. Vehicles with normal aspiration (and some with turbos)with direct injection and/or both direct and port injection typically can be run on regular unleaded. The 2017 Toyota 4 Runner will run on regular unleaded (it has standard port fuel injection), there’s no benefit to using premium. > [@ClarkTuck](#): > > I think it is mainly because high octane fuel increases fuel mileage slightly. Only when the engine has been designed/tuned to take advantage of premium fuel. Otherwise there’s no real difference in fuel economy. > [@ClarkTuck](#): > > But high octane fuel costs a lot more than the small increase in mileage. Depends. On vehicles that recommend premium, but require regular, there will be a difference in both fuel economy and power. A good example of this the Ecboost 4 cylinder Ford uses in the Mustang.When it came out it was rated for 310 HP when running on 93 octane. On 87 octane it’s output fell to around 275 HP. Which is noticeable. Fuel economy also drops, for some cars you’re still money ahead using regular, on some others, it’s a wash or a slight money-losing proposition. > [@ClarkTuck](#): > > I think that as long as an engine does not make strange sounds with regular octane fuel it is not doing any harm to the engine. Please let me know what you think. You’re best off using the recommended fuel as stated by the manufacturer. You should always use at least the required fuel. _Recommended_ and _Required_ are not the same thing. If your owner’s manual recommends premium you can likely get away with using regular without ill-effect other than reduced power and fuel economy. If premium fuel is required then that’s what you should use. Using lesser fuel can potentially lead to problems (holes in pistons for example). ---
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [November 14, 2018, 4:03am UTC](https://community.cartalk.com/t/2017-toyota-4runner-premium-fuel/128632/14 "2018-11-14T04:03:12Z")
> [@ClarkTuck](#): > > How do I know that you are someone that knows what they are talking about or just someone that has an opinion? On internet forums like this or any other there’s no way to know. Any post here could be a 13 year old kid waiting at a bus stop w/nothing to do until the bus arrives. If you need to be sure you are getting an expert’s advice, the place to obtain that is at the dealership or your local well-recommended auto repair shop. Bring your wallet. It is possible to assess what a poster has said on prior threads by clicking on their handle, so that’s one method to make your own appraisal of the merits of their comments.