How to Show Ethanol Content on Your Dash with KrispyGauge

If your car runs on E85 or a flex-fuel blend, the ethanol content in the tank is the one number your tune depends on that you can't see. Pump E85 isn't always 85% ethanol — it varies between stations and through the year — and topping up a half tank of 98 with E85 leaves you with something in between. Your flex-fuel sensor already knows the real figure. KrispyGauge puts it on your dash, live, as a big clear readout in a standard 52mm gauge pod.

What you need

• A KrispyGauge on the same CAN bus as your ECU.
• An ECU that knows the ethanol content. On an aftermarket ECU that means a flex-fuel (ethanol content) sensor wired in and set up in the ECU. On a factory car it means the ECU reports ethanol content over OBD2 — see below.

KrispyGauge doesn't connect to the sensor itself. It reads the figure the ECU has already worked out, over CAN, so if your ECU shows ethanol content in its software, KrispyGauge can show it on the dash.

Aftermarket ECUs that work

KrispyGauge reads ethanol content from these ECUs' CAN data:

• Haltech (Nexus, Elite, Rebel) — Haltech signals
• MaxxECU — MaxxECU signals
• Emtron — Emtron signals
• rusEFI — rusEFI signals

Link, Holley, Megasquirt, AEM Infinity, EcuMaster and Syvecs ECUs work with KrispyGauge for other readings, but KrispyGauge doesn't currently read ethanol content from them.

Factory cars over OBD2

OBD2 has a standard reading for ethanol fuel percentage, and KrispyGauge supports it. Plug in through the OBD2 port and, if your car's ECU reports it, the ethanol content shows up like any other reading.

Not every car reports it. Plenty of factory ECUs don't share ethanol content over OBD2 at all — including some cars that are flex-fuel from the factory — and if the ECU doesn't send it, no gauge can display it. The quickest way to find out is to add the Ethanol reading to a page (below): if no value ever appears with the engine running, your car doesn't report it. Our OBD2 supported vehicles list covers what's been tested so far.

Setting it up

1. Turn the ignition on, and on your phone or laptop join the gauge's WiFi network, Krispy_XXXX (the full name is shown on the gauge at boot). The password is GetKrispy.
2. Open http://4.3.2.1 in your browser to reach the KrispyGauge Web UI.
3. Under Settings, choose your ECU type — Haltech, MaxxECU, Emtron, rusEFI or OBD-II.
4. Under Page Config, pick a page and set its channel to Ethanol. A single dial or a large number both work well; the reading runs from 0 to 100%.
5. Save, and the gauge shows your live ethanol content.

Full details on connecting are in the Web UI guide.

Set a warning for a weak blend

A reading is good; a warning you can't miss is better. In the Web UI, give the Ethanol page a warning threshold just below the blend your tune expects. If a tank of fuel comes in weaker than it should, the gauge flashes a full-screen alert before you lean on it — not after.

KrispyGauge has several pages, so ethanol content can sit alongside boost, oil pressure, coolant or AFR and you can flick between them, or put ethanol on a gauge of its own.

Common questions

Can KrispyGauge read my flex-fuel sensor directly?

No — it reads ethanol content from the ECU over CAN. The sensor needs to be wired to, and set up in, your ECU.

Will it work on my factory flex-fuel car?

Only if the car's ECU reports ethanol content over OBD2. Many don't. Add the Ethanol reading and see whether a value appears with the engine running.

Does it fit my dash?

KrispyGauge comes in 52mm and 60mm, to suit standard gauge pods and panels.