RadMon

Seems the opinions differ from 5% power increases with premium, to Nissan and the FTC which claim there is absolutely no reason to use premium gas whatsoever, to Mercedes which only guarantees their published figures when using premium, to the SAE which states that using preimum might even degrade performance.

A research chemist at Honda who drives an Acura is quoted.

I'll stick with premium, thanks!

Why use premium gas when regular will do?

nuke

My feelings, exactly

gogozy

good read!!! now i know puel regular won't void warrenty!!

ClutchPerformer

I'll pay that price to know that my engine won't knock under hard acceleration. The article downplays the significance of a knock, and implies that knock sensors on modern engines can prevent it. They can't! In fact, they can't even change anything until they "hear" a knock. By that time the damage has been done, and if it happens too often, your engine is shot.

Let's not forget that we have a 10.5:1 compression ratio. I'll stick with premium, thanks. Good find, RadMon!

dom

I think the bigger issue here is that our TSX owners manual specifies that we do not use gas with MMT (Can't remember what that stands for) Gas with MMT apparently causes a buildup somewhere in your engine which can evebtually ruin the engine ??

The only gas here in Canada apparently is Sunoco 94 Octane. So instead of me putting in Sunoco, Shell or whatever 91 or 92 Octance I put the 94 because it does'nt have MMT. I pay 12 Cents a litre more over regular which works out to $6.00 more a tank and 0.2 Cents a litre more over a 92 Octane which is only $1.00 per fill up. There's no way I'm going down to 87 so even if I put in 92 I'd only be saving maybe $60.00 a year which is'nt worth my peice of mind.

larchmont

Yeah, "principal chemist" at Honda Research & Development -- drives an Acura.

Sounds like a good candidate to answer Chad and Brad about why to have an Acura and not a Honda.

ebcheon

i think i'll stick w/ premium for the 5% performance increase.

soopa

theres alot more to it then how simplified you guys are making it....

you should read some of the posts on A-CL about this. theres alot of intelligent and talented engineers over there with a swell of knowledge on the subject... very interesting reads.

vitocorleone

I use premium in my '96 Integra because I notice a tangible difference in acceleration and overall "smoothness" of engine operation, especially up hills. I don't need a chemist to tell me anything on this issue one way or another. I would wager it varies from car to car, as well.

HIP

In 1999 when I bought our Odyssey EX, Honda said the engine would develop 210 hp (on 91 octane) fuel. They made no mention anywhere that running it on lower octane would be detrimental to the engine or warranty. In fact, they even suggested that running on lower octane fuel would only decrease horsepower/performance down to 205 hp. In 2002, the same engine was "improved" and developed 240 hp while running on regular or low octane fuel.

Most people speculated that a different cam, lower pressure exhaust and/or cpu or eprom was used and that was it. The feeling was and still is that Honda designs engines that can be easily upgraded in performance during a particular models lifecycle. In other words, it is possible that within the TSX's 4-5 year lifecycle, it will receive at least one to three performance upgrades on the same engine without significant costs to Honda.

What all this boils down to is this, Honda says to use Premium or 91 octane in the current version of the TSX, probably due to its high compression ratio, this will prevent "pinging" or detonation. You could argue the computer eprom should retard timing significantly enough to reduce or eliminate this from happening and it does. But the problem now becomes that of heat. As the engine timing is continually retarded, power is diminished. At the same time the engine's operating temperature is also elevated. Running at higher engine temperatures is bad. It creates multiple issues, not the least of which is excessive cooling system pressure and stain, catalytic converter problems, possible carbon build up on the valves, etc.

As the article indicates, it's tough to decide between logic and cost. IMHO, I would say that using Premium is the best choice, however, running mid or low level fuels "occassionally" should not create any lasting damage if not done too often.

Brad

Call it "squid" or "calamari", it's all the same idea for the analogy. It's marketing. I'm no slave to marketing perceptions and brand label engineering.

If the chemist is driving an Acura, he's still driving a Honda, bar none. The NSX, MDX, RL, TL, and RSX are all marketed as Hondas outside of North America. The RSX is currently the Honda Integra, the RL is currently the Honda Legend, and (here's a reverse twist) the Acura MDX is a Honda MDX, for example. It's all Honda, thank goodness.