Nezumi

Just picked up my 450 last night and I was reading through the manual and I noticed that it said 91 octane or better. However my sales guy told me that both the 350 and 450 run totally fine on 86. What has been your experience on this? I found it weird that it was conflicting, because I thought that if anything, the salesman would say it required premium.

vlad_a

Your salesperson is incorrect, 450h requires 91.
From my experience, when you run on 89, you get 2MPG less than 93.
You can also hear the engine working harder.
Not worth it, IMHO.

Droid13

Search the forum and you'll find lots of discussion about this on both sides, plenty of logic, facts, figures, opinions, and first hand experiences.

Unless you experience a specific and noticeable issue with your octane choice, the choice of fuel can be put into the same category as your choice of politics, religion, and belief in alien abductions. A notable quote from a well known SciFi character, "Put logic aside, do what feels right".

I've been struggling on this issue for quite some time. Here in Canada, 91 octane is already significantly more expensive than our already more expensive gasoline, about $0.55 more per US gallon that 87 octane fuel. I've fueled up with 91 because that's what the manual says, and it's not so much the extra cost itself but the annoyance of handing my money over to the gas companies that makes me occasionally fill up with 89 or even 87. I find no difference in performance that I can reliably define. Sometimes I talk myself into believing it performs better with 91, but some days not so much. I've tried to track mileage and again, sometimes I get really good gas mileage, but then it doesn't jive later. Last tank I used midgrade 89 and got the best mileage on a tank I've had for some time, so I decide to fill up with 91 from the same station, and now my mileage has gone down. What was really different, so hard to tell. That's why I follow the quote above, do what feels right. If it brings you comfort to put the recommended fuel in, do so. If it irks you to no end handing over more money if you don't 100% need to, don't unless you have to and spare yourself the irktation (I'll take credit for that new word!).

Nezumi

Both valid points. I'll see if I can dig up the old posts I saw on the forums before. The reason I brought it up is because I've never heard a sales person say that.

vlad_a

Andy, what may really affect the results is that the gas stations sometimes downgrade the gas.
They could very well put 91 into 87 tanks and you wouldn't know any better.
For us, up North in US, the Premium price difference is about 20-40c/gal. When we took a road trip South, the Premium prices were much higher compared to 87 and 89. That's when I decided to experiment with 89 a bit again.

Nezumi

I just always go to costco for my gas for the past 5 or 6 years. I've never had any issues there. Premium is still about 30 cents more, but I haven't owned a vehicle that took regular in such a long time, it's probably not that big of a deal. I just was surprised because I was under the assumption that 87 was the required octane, only to find that it was not the case after reading the manual.

Cruiter

You're already buying good gas so nothing's changed. As for the salesperson he was either seriously lacking in product knowledge or just thought you'd be an easier sale if you thought you could fill with regular (OK in an emergency but not on a routine basis). Either way he shouldn't be selling until he can quote accurate requirements. I'm twice retired, once from the Navy and once from the retail end of the car business. We'd take that person off the floor and offer a retraining period. If that failed, well so would he .... Permanently!