I have yet to find any dealership where the EV specialist knows anything about EVs and isn’t an asshole. I’ve been browsing cars for over a month now, and 99% of car dealers have one of two things:
- A guy that knows nothing about EVs, but thinks he does.
- A guy that knows things about EVs, but will outright lie to you.
Sometimes this applies to the car itself - sure, it’s got the preheat. Oh you want it in writing? Okay it doesn’t have the preheat, I admit it.
More often this applies to the tax rebates. Hyundai dealers in Connecticut were illegally applying the state and federal EV credit to cars above 50k MSRP, and when called out on it are just like “c’mon, you’ll get it.” Like dude, you’re ASKING me to defraud the IRS?
Today, I dealt with these assclowns: 2021 Ford Mustang Mach-E Select (autohausinc.com)
“Qualifies for up to $7500 in tax credits.”
No, it doesn’t. The used EV credit is for 25k and below. This is 27.5. It will not get a dollar. I talked to them about this… and got willful denial every step of the way, to the point that I showed them the IRS policy, pointed out the exact wording, and told them no one on earth would be eligible for it, to which they kept telling me “not all buyers are qualified.” I’m like, no one can get a dollar back from the government for that car. Take that off your website.
The response? " Without an application we cannot answer if you will personally qualify, but we know for a fact there are credits available for our car. I apologize if you feel mislead."
I’m just so frustrated. It shouldn’t be this hard to find a worthwhile used EV under 25k or a new EV under 50k, but everywhere in Connecticut it seems the dealerships play it up and mark the new MSRPs over 50k and the used EVs around 28-33k, and almost all of them then still act like you’d still get the rebates. I’m happy to be smarter than that, but I feel sorry for all the people in Connecticut who will fall prey to the assholes at Hyundai dealerships and used car dealerships in this state.
Octane rating refers to the fuel’s resistance to detonation. There is no difference in power per unit volume in 85 vs 93 octane fuel. The salesman believes in a common misconception that higher octane means higher power, but this is not how fuel works. His “summer” comment likely was in reference to the fact that warmer air produces less power than colder air. Living in Phoenix where daytime temps over concrete in the mid 120’s is common, this can be a noticeable difference. He was saying to run higher octane to make up for the power loss.
What makes this comment hilariously wrong is that you would actually want to run higher octane in colder temperatures, not warmer. Hot air has the effect of increasing the density altitude, that is, it makes the air less dense. The less dense the air is, the less air is available for the engine which means it won’t be able to increase the fuel-to-air ratio high enough to knock anyway. This is why you can run lower octane fuel at very high altitudes, its common to see 83 octane pumps in the Rockies.
There are some engines which will make noticeably more power on higher octane but can run on lower octane. These are typically high performance turbo charged engines and the ECU’s are basically programmed to push timing and AFR as far as they can until the car begins to knock.
The Atlas VR6 is already running at an 11:1 compression ratio and is rated for 87 per VW. People have actually pulled the timing logs on the VR6 to check if the engine is able to identify 93 octane fuel and the answer is yes, it can, but the difference is maybe 5 horsepower in the best conditions, which is about what you’d expect given the engine’s characteristics.
I run premium gas just to avoid carbon fouling on my direct injection engines and I put more roadtrip (interstate) miles on in the summer so I tend to run premium gas then. Rev it up nice when it’s warmed up for a little bit of a nice Italian tune up.
So they may not be totally full of beans.
You’re probably wasting your money on premium gas. Unless your vehicle’s owners manual specifically says that it requires high-octane fuel, as AlphaThree explained above, there is no advantage to running premium gas. I know, it’s a hard concept to grasp because we have been inundated with marketing BS from the oil companies for YEARS…
It has been studied extensively that direct injection engines benefit from either using high quality premium fuel or using fuel additives like jettronic to avoid walnut blasting.
I’ve opened up many 2.0 TSI of multiple generations in my time at VW/Audi and have seen first hand. That’s why I bought my A4 Allroad. It has multiport injection and that cleans the valves (especially with nice fuel as I stated). My wife’s Tiguan is not so lucky.
If you have studies, please cite them, but sweeping statements about big oil don’t do it for me.
Here’s Consumer Reports: https://www.consumerreports.org/cars/fuel-economy-efficiency/top-tier-gasoline-worth-the-extra-price-a7682471234/#:~:text=The results showed that on,chamber than Top Tier gasoline.
I doubt this makes a difference. Like the previous commenter said, it’s about knock resistance.
Gasoline is sold by volume, not weight. So due to expansion in a liquid as warm molecules move away from each other, you get less fuel from a warm gallon pumped in the summer than a cool gallon pumped in the fall.
Mazda had to do some clever engineering to get those engines rated to run on 87 at all lol. They some trick with the exhaust gases to lower the temperature inside the combustion chamber and prevent detonation. The SkyActiv engines might be the highest compression engines currently produced that can run on 87. I bet there’s a website somewhere that tracks that.
I wonder if that’s related to the clatter for 30 seconds or so when it starts up. It almost sounds like a diesel. I’ve read it’s due to heating up the pre-cat in startup in the skyactive engines.
So is it fair to say engines that require higher octane fuel are not designed as well as engines that run fine on lower octane fuel since they can’t figure out how to run without knocking on the lower octane fuel?
I can see how you would think that, but not really. It’s more about the manufacturer goal. High performance engines are almost always going to be tuned for the highest octane available. This is so they can have the most aggressive timings. Forced induction engines most often require high octane fuel or will make significantly more power on higher octane fuel (assuming they have the appropriate tune).
Best example is the VW 2.0T EA888 engine. It is rated for 87 on VW cars but 91 on Audis and Porsches. Same engine, different tunes to meet the expectations of different customers.
Thank you for the detailed explanation.
My VW 2.0t is rated for 91 octane (2012 German-made CC), and I thought all of the 2.0t engines were tuned for premium fuel. A turbo that isn’t tuned for 91 octane seems like a wasted opportunity. (and you don’t really save money by running cheaper lower octane fuel, as you get lower mpg when the engine timing has to compensate for the lower octane)
I agree. They switched the minimum rating to 87 on the 4 cylinder TSFI’s a few years ago. For the GLI/GTI, I’ve heard they put a note in the manual with an asterisk that says “advertised power number achieved on 93 Octane”. The Golf R I believe still says 91 minimum (thank god).
I follow this subreddit, as I’ve been ready for an EV for a couple years. I swear I’m not here to troll with my ICE rants.
I’ve only had turbo cars for the last 20+ years, and it’s amazing how much more power they make with 91-93 octane compared to 87 octane. The extra mpg on premium offsets the cost, with the benefit of driving further between refills. Altitude makes the difference even more pronounced.
On a related note, it’s amazing how well Saab in particular can take advantage of added ethanol compared to VW. My previous Saab made seriously more calibrated butt-dyno hp when running e25-e35 compared to e10 (35% ethanol was as far as I was willing to go with the stock injectors). My current VW doesn’t show similar improvement (I assume the VW fuel map/ecu has much narrower limits, or that I’ve hit the limit of the injectors to deliver the extra fuel required). Again, altitude can be a huge factor; I’d think non-turbo cars would REALLY shine when fed more ethanol (oxygen) when the car can’t get it from the ambient air and the engine can’t force-feed more air.