# 2014 Lexus RX 450h - What if I skip Premium? **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** lexus\ **Created:** [September 18, 2019, 2:54pm UTC](https://community.cartalk.com/t/2014-lexus-rx-450h-what-if-i-skip-premium/149015 "2019-09-18T14:54:29Z")\ **Posts on this page:** 11\ **Page:** 3
**Author:** ![shanonia](https://avatars.discourse-cdn.com/v4/letter/s/9de053/32.png) [@shanonia](https://community.cartalk.com/u/shanonia)\ **Post date:** [September 25, 2019, 5:47pm UTC](https://community.cartalk.com/t/2014-lexus-rx-450h-what-if-i-skip-premium/149015/41 "2019-09-25T17:47:35Z")
Without premium, the engine will not provide optimum performance. Less-than-optimum performance may be good enough for most drivers most of the time. I’d probably give regular a try because I’m curious, like to save money, and don’t fear permanent damage from trying it. ---
**Author:** ![Waterbuff](https://avatars.discourse-cdn.com/v4/letter/w/f07891/32.png) [@Waterbuff](https://community.cartalk.com/u/Waterbuff)\ **Post date:** [September 25, 2019, 7:20pm UTC](https://community.cartalk.com/t/2014-lexus-rx-450h-what-if-i-skip-premium/149015/42 "2019-09-25T19:20:17Z")
> [@TwinTurbo](#): > > But the provision to use regular does not have the same meaning without the caveat that immediately follows it. > > To me it says premium is required. Regular can be used in a pinch but if you continue to do that, engine damage is likely. > > That’s not a recommendation by my reckoning. Ymmv. this interpretation of the same words is interesting – the particular portion you highlighted with bold includes “ **may result in engine knocking. Per-sistent knocking can lead to engine damage** ” which to you means “premium is required” (and despite the use of “may result” and “can lead to”, rather than ‘will result’ and ‘leads to’, you view the outcomes as “likely”) frankly, I have no problem with each person interpreting it the way they want or like – it is a free country and freedom of thought is very important to me; I do have a problem with Lexus using the different wordings between its manual and its webpage and I wonder if you would be so kind as to let me know if you interpret the following two examples differently: 1. “Premium unleaded gasoline with an octane rating of 91 (Research Octane Number 96) or higher required for optimum engine performance.” 2. “Premium unleaded gasoline with an octane rating of 91 (Research Octane Number 96) or higher required.” #1 is from T; #2 is a truncated version which I would interpret differently from #1 ---
**Author:** ![asemaster](https://avatars.discourse-cdn.com/v4/letter/a/5f9b8f/32.png) [@asemaster](https://community.cartalk.com/u/asemaster)\ **Post date:** [September 25, 2019, 7:53pm UTC](https://community.cartalk.com/t/2014-lexus-rx-450h-what-if-i-skip-premium/149015/43 "2019-09-25T19:53:10Z")
The ongoing discussion about what required means and what recommended means has no definitive answer, but I think everyone agrees that in a car where premium is recommended or required, there will some loss of performance. Might not be noticeable by most people, but it’s there. In returning to the original question, which is posed many different ways on this forum… Can someone who wants to use regular instead of premium please do some math, with miles traveled, gallons used, and price of fuel, and demonstrate the supposed savings of using regular. I’ll bet it’s pocket change, no more than the price of a sandwich per week. ---
**Author:** ![TwinTurbo](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@TwinTurbo](https://community.cartalk.com/u/TwinTurbo)\ **Post date:** [September 25, 2019, 8:10pm UTC](https://community.cartalk.com/t/2014-lexus-rx-450h-what-if-i-skip-premium/149015/44 "2019-09-25T20:10:33Z")
> [@Waterbuff](#): > > rather than ‘will result’ and ‘leads to’, you view the outcomes as “likely” Yeah, because I understand what knocking is and what is mechanically happening to the engine components when engine knock is occurring. > [@Waterbuff](#): > > and I wonder if you would be so kind as to let me know if you interpret the following two examples differently: > > 1. “Premium unleaded gasoline with an octane rating of 91 (Research Octane Number 96) or higher required for optimum engine performance.” > 2. “Premium unleaded gasoline with an octane rating of 91 (Research Octane Number 96) or higher required.” Most definitely. The second one being far more restrictive as it does not detail the impact of non-conformance. > [@Waterbuff](#): > > I do have a problem with Lexus using the different wordings between its manual and its webpage It is misleading. I would never rely on a sales brochure (or web page) as the final word on anything technical. Puffing is going on there. Not unlike the very small print on any advertisement be it print, electronic or TV. The User Manual would be a better source for accurate information. ---
**Author:** ![Waterbuff](https://avatars.discourse-cdn.com/v4/letter/w/f07891/32.png) [@Waterbuff](https://community.cartalk.com/u/Waterbuff)\ **Post date:** [September 25, 2019, 9:22pm UTC](https://community.cartalk.com/t/2014-lexus-rx-450h-what-if-i-skip-premium/149015/45 "2019-09-25T21:22:54Z")
> [@TwinTurbo](#): > > Most definitely. The second one being far more restrictive as it does not detail the impact of non-conformance. thank you for your reply ---
**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:** [September 25, 2019, 9:27pm UTC](https://community.cartalk.com/t/2014-lexus-rx-450h-what-if-i-skip-premium/149015/46 "2019-09-25T21:27:35Z")
Folks can do to their own cars what they want. When I’m asked a question by someone I don’t know, with unknown automotive abilities, I will always keep it simple. And simple is “required” means “required”, “recommended” means you can try it out and see. And the OP’s owner’s manual provides clear direction - use premium to avoid knocking and potential engine damage. If you have to use some regular, fill back up with premium as soon as you can. ---
**Author:** ![circuitsmith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/circuitsmith/32/40376_2.png) [@circuitsmith](https://community.cartalk.com/u/circuitsmith)\ **Post date:** [September 26, 2019, 3:34pm UTC](https://community.cartalk.com/t/2014-lexus-rx-450h-what-if-i-skip-premium/149015/47 "2019-09-26T15:34:42Z")
I’d try 89 or 87 in cold weather (as I posted before). Conversely, some cars spec’d for 87 run better with higher octane in hot weather. ---
**Author:** ![Waterbuff](https://avatars.discourse-cdn.com/v4/letter/w/f07891/32.png) [@Waterbuff](https://community.cartalk.com/u/Waterbuff)\ **Post date:** [September 26, 2019, 5:16pm UTC](https://community.cartalk.com/t/2014-lexus-rx-450h-what-if-i-skip-premium/149015/48 "2019-09-26T17:16:32Z")
> [@texases](#): > > And simple is “required” means “required” you’ve said that more than once – yet you won’t answer a simple comparison of the word “required” being used: makes a person wonder _ **what is so hard** _ about answering whether you interpret the following two examples differently: 1. “Premium unleaded gasoline with an octane rating of 91 (Research Octane Number 96) or higher required for optimum engine performance.” 2. “Premium unleaded gasoline with an octane rating of 91 (Research Octane Number 96) or higher required.” #1 is from your (much earlier) comment #2 is a truncated version which I (and at least one other commentator) interprets differently from #1 ---
**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:** [September 27, 2019, 2:49am UTC](https://community.cartalk.com/t/2014-lexus-rx-450h-what-if-i-skip-premium/149015/49 "2019-09-27T02:49:46Z")
Why would I answer this? You left out the key part of the paragraph. So the complete paragraph is clear-premium is required to prevent engine damage. Simple. ---
**Author:** ![Waterbuff](https://avatars.discourse-cdn.com/v4/letter/w/f07891/32.png) [@Waterbuff](https://community.cartalk.com/u/Waterbuff)\ **Post date:** [September 30, 2019, 6:38pm UTC](https://community.cartalk.com/t/2014-lexus-rx-450h-what-if-i-skip-premium/149015/50 "2019-09-30T18:38:27Z")
> [@texases](#): > > Why would I answer this? You left out the key part of the paragraph. So the complete paragraph is clear-premium is required to prevent engine damage. Simple. sounds like a deflection – why would “the key part of the paragraph” (or the rest of the paragraph) be needed if Lexus used 1. “Premium unleaded gasoline with an octane rating of 91 (Research Octane Number 96) or higher required.” ---
**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:** [October 1, 2019, 2:27am UTC](https://community.cartalk.com/t/2014-lexus-rx-450h-what-if-i-skip-premium/149015/51 "2019-10-01T02:27:12Z")
Ok, you win, the writer of that passage should be whipped with a wet noodle for this grammatical imprecision. [Previous page](https://community.cartalk.com/t/2014-lexus-rx-450h-what-if-i-skip-premium/149015.md?page=2)