We Motor Medics are just gearheads and mechanics who would rather be in the shop working on cars. We’re not here to push an agenda, but we are here to share our knowledge, and we think we’ve earned it by putting in years of work in the shop.
We’ve been full-time gearheads for almost 40 years, so we do know a thing or two about cars.
As always, we’ve recently seen a lot of engine repairs, and none of them have been due to bioethanol use. We had a few cars that needed general tuning maintenance done to get them running at their best again, and when they were running poorly, some customers claimed that they ran worse when using biofuel — except one, that is. This customer said the car would only run well when using higher bioethanol blends.
This person came to our shop and said, “My car runs poorly on non-bioethanol fuel but is fine on E85.” He uses E30 almost exclusively, so when he had to get E10 on a road trip, he found that his car ran poorly. As a regular user of bioethanol who had hands-on experience with how it works in his vehicles, he wanted to know what was wrong with his car.
On the other hand, we had two customers who immediately thought it was the bioethanol making their cars run poorly.
So, what was the problem with these cars?
As a general rule, your car needs to be in good running condition to get the best mileage and performance it is capable of. If your car has vacuum leaks, leaking injectors, or even worn spark plugs, it will affect the fuel mileage and hinder performance. When you operate a car that needs repair — even if the check engine light isn’t on — and start using different fuel types, you can make those issues more noticeable, and they can make you think the fuel is the problem.
The two that ran poorly only while using E10 or higher were both running lean, even when they came in using non-bioethanol fuel. In fact, they were almost ready to turn on a check engine light because they were so lean. One had a vacuum leak, and the other needed a mass air flow sensor. After repairing them, the cars both ran perfectly with E30 in them. The bioethanol user whose car ran poorly on regular fuel had a leaking injector and was running rich all the time.
If you’re dealing with vehicle issues, it’s not caused by the fuel. It’s likely a deeper issue that needs repairing. That’s why it’s important to keep your vehicle in peak condition — and a good idea to choose bioethanol — to maximize fuel performance, save money, and keep your engine running better for longer.
The Motor Medics Under The Hood can be found on a station near you or your favorite podcast site.