How can we help?

Choose Get started. Continue with ChatGPT, use Google when available, or create an email/password account. Verify your email from your inbox before signing in. In My garage, add your vehicle’s year, make, model, and current mileage. Engine, VIN, and nickname are optional. Then log a past service or set your first reminder. Use the same login on each device. Existing ChatGPT users should connect Google or create, verify, and connect an email login from Account before opening a separate garage. For Google, use a normal Safari or Chrome browser and allow the sign-in popup.

Yes. For cars and trucks, add a vehicle with its VIN and choose Fill details from VIN to retrieve available identification details from NHTSA. Or enter a year and make to get model suggestions; you can always type your own details. Vehicle lookup does not set maintenance intervals. Service names suggest your saved reminders, matching past services, and common jobs. Selecting one fills reusable details and checks a matching reminder; review the checkboxes before saving. Shops, fuel stations, and expense vendors suggest names from your current garage. New fuel entries remember that vehicle’s last station and fuel type. Costs, invoice numbers, and new odometer readings are not copied from old entries. Every suggestion remains editable.

Yes. Choose DIY upkeep for your oil changes and routine maintenance, or Shop visit for work performed by a shop or dealership. Shop entries include invoice numbers and warranty notes. Both appear in your history and full service report.

Automatic VIN schedule lookup needs a vehicle-data connection. When available, results are labeled mileage milestones from Vehicle Databases, with the returned vehicle identity and retrieval date. They are not automatically treated as recurring intervals or completed/overdue work. Engine-specific, time-based, and severe-use coverage still need your exact manufacturer manual. Open the Manufacturer guide, find the exact model year, engine, and driving conditions, then choose Read maintenance pages. Upload a photo or a PDF excerpt of up to 10 pages, or paste the instructions. The helper finds explicit repeating intervals in sentences; it does not reliably interpret schedule tables or condition-based dashboard alerts. Review and correct the rows, select the ones that apply, and confirm before importing. You can also add intervals manually. Last-service history starts blank.

The garage opens with every vehicle in one overview. Quick mileage update lets you enter today’s readings together; leave unchecked vehicles blank. Readings older than 30 days are flagged. Open a vehicle’s logbook to correct a lower reading or record work.

Yes. Use Shop follow-ups for work recommended but not completed during a visit. Save the shop, link the visit, and optionally add a follow-up date or odometer. Close, reopen, or snooze reminders. Closing a follow-up does not log completed work.

Use Vehicle warranties for manufacturer coverage and extended policies. Save separate entries for bumper-to-bumper, powertrain, or other plans, including the provider, contract number, and expiration date or ending odometer. Status uses your entered limits and last mileage reading; coverage comes from your policy. Existing repair warranty reminders remain under History, and new parts or labor coverage can be noted on the service entry. Both warranties and shop follow-ups appear separately in reports and account exports.

Set a mileage interval, a month interval, or both. If you set both, the earlier threshold determines when the service is due. Add the last completed mileage and date when known. When logging a service, check the reminders it completes. Update your current odometer regularly so mileage reminders stay useful. Unknown history is flagged instead of guessed.

Under Account, Email preferences shows the current delivery status and a preview of your garage summary. Email delivery is waiting for its service connection. Once connected, you can opt into weekly attention reminders and a monthly summary, pause delivery, or unsubscribe. No one is automatically enrolled. Push notifications are not enabled. In Service plan, download calendar reminders for services with a known time-based due date. Import the ICS file into your calendar and check its notification settings. Events request an alert one day before, but your calendar controls delivery. This is a snapshot, not a live subscription: after logging work, remove old events and import a fresh file. Mileage-only reminders require checking the garage and updating your odometer.

Choose Scan receipt while logging a service. Upload a clear JPG, PNG, or WebP photo, or a PDF with selectable text. English text is read on your device and recognizable fields are drafted for review: date, mileage, total, shop, work, and invoice number. Check every field before saving. The receipt is selected as an attachment; nothing is saved until you save the service. Scanned-image PDFs should be supplied as photos. HEIC files can be attached but are not scanned.

Yes, with Family: $10/month after the free trial, unlimited vehicles, and up to 6 users total including the owner. Individual is for 1 user and 2 vehicles. Pending invitations reserve a user place until accepted, revoked, or expired. Choose Household users from your garage or Account. Enter the email your spouse or household member will use, create an invitation, then copy or share the private link. They can sign in or create an account before accepting. Underhood does not send the invitation email. Invitations expire after 7 days and can be revoked. Members can view and edit garage records, but only the owner can remove whole vehicles or clear the garage. The owner can remove member access at any time. Your existing personal garage remains separate; switch garages from Account.

Attach files while logging a service, or open Files and choose Upload. PDFs, JPGs, PNGs, WebP, and HEIC/HEIF photos are supported, up to 10 MB per file. You can attach several receipts to a service or keep an owner’s manual as a vehicle document.

Yes. Choose Add vehicle / RV, then select a motorhome, travel trailer, fifth wheel, pop-up, truck camper, or other towable RV. Existing vehicles can be reclassified in Vehicle details. Each RV has its own services, shop visits, receipts, warranties, follow-ups, and reminders. Towable mileage is optional; set month-based intervals and a last completed date for seasonal upkeep. The Service plan includes RV task suggestions such as winterization, roof inspections, water systems, and appliance service. Enter the correct intervals from your RV or component manual; suggestions do not supply manufacturer intervals. Generator hour readings can go in service notes, but automatic hour-based reminders are not included. RVs count toward your plan’s vehicle allowance.

Open All vehicles → Costs & budgets, or Reports → Overview in any logbook. Select one vehicle, cars/trucks/vans, RVs only, or the entire garage. Choose the dates you want to measure. Your garage budget shows each vehicle and the combined monthly average; quarterly and yearly budget estimates multiply that average by 3 and 12. The same calendar months are used for every vehicle so averages add up, including months with no entries and partial months. Missing purchases or history can understate the result. Group spending history by month, quarter, or year to see actual totals and running averages, then export the budget CSV or print a report. These are running costs, excluding insurance, registration, purchase price, financing, and depreciation.

Use Add expense → Propane for an RV propane purchase and attach the receipt. Log tow-vehicle fuel on the car or truck that bought it so the garage budget counts it once. Generator fuel can be recorded as Other running costs. MPG is calculated for road vehicles and motorhomes using propulsion fuel, and is not calculated for towable RVs.

Choose Add fuel in your garage. Enter the purchase date, actual odometer, US gallons, total paid, and whether you filled the tank completely. Attach a receipt if you like. Reports → Overview shows fuel, oil changes, repairs, and other running costs for one vehicle or all vehicles. Use Add expense for DEF, tires, towing, inspections, and other costs not already on a saved invoice. Insurance and registration are not tracked.

MPG uses total miles and gallons between full tanks, including partial fills. Every fuel purchase must be logged. Flag a missing purchase to start a new interval. Missing odometer readings also restart MPG. Fuel intervals are selected by their ending date. Monthly averages divide recorded spending by calendar months in the selected range, including partial months. Cost per mile uses expenses paid between actual odometer readings inside that range, and shows excluded costs when coverage is incomplete. No missing mileage is estimated.

Edit a service and choose its cost category. For mixed invoices, split the total across categories; all amounts must add up to the invoice total, including tax and fees. The invoice is still counted once. Older maintenance stays in Other maintenance until you categorize it. Service history uses the work date; cost charts use the paid date if you enter one.

Select a vehicle and open Reports → Service reports. The report includes all saved services, fuel purchases, running expenses, spending, shop and invoice details, warranty notes, a receipt index, and a separate reminder section. Print / save as PDF uses your browser’s print menu. Download report saves a standalone HTML copy. Export history CSV opens in spreadsheet apps.

Choose Report + original receipts ZIP to download the report and every original receipt together. Extract the ZIP, then open service-report.html; its receipt links open the files in the included receipts folder without sign-in. Standard PDF/HTML reports still list receipts separately. Review all documents before sharing because they may contain your VIN, address, and other personal details.

Yes. Open Underhood in your phone’s browser. On iPhone, use Safari’s Share menu and Add to Home Screen; on supported Android browsers, look for Install app or Add to Home screen. Open the site in Safari or Chrome first if you are viewing it inside another app. Launching from the home screen opens directly to your garage. An internet connection is required to load and save records; after your first online visit, an offline screen helps you reconnect. If a save fails, keep the form open and retry.

Every user agrees to the current Underhood Terms of Service before accessing the app, including household members and people using Google or ChatGPT. The app records the accepted version and date. Existing users review the terms on their next visit. This does not authorize subscription charges. You can read the terms from the footer and submit questions using Help & account requests in Account or on the restricted-access screen.

Individual is $5/month for 1 user and 2 vehicles. Family is $10/month for unlimited vehicles and up to 6 users total, including the owner. Both include all current and future app features. These are monthly prices, not one-time purchases. Early access is free while payments are paused. Plan limits apply now; choosing a plan does not start billing, authorize future charges, or automatically enroll you in a paid subscription. Choose a plan in Account. Existing larger or shared garages retain free Family access so records and memberships are preserved. You must fit Individual limits before switching down; the app never deletes records or removes members to make a plan fit. Both plans include a 30-day free trial once subscriptions launch. No card is required. Your trial starts on your first app or account visit after launch and acceptance of the current terms. After 30 days, choose whether to subscribe: Individual is $5/month; Family is $10/month. Saved records remain viewable and exportable if you do not subscribe. Complimentary accounts stay free.

Open Account to download all garage data as a JSON file. Original receipt files are downloaded separately. You can also permanently clear your entire garage from Account after typing the confirmation phrase. To remove a single vehicle and its records, open Vehicle details and choose Remove. Clearing your garage does not delete your ChatGPT or Firebase sign-in account.

Check your connection and keep the form open so you can retry. If a service saved but a receipt upload failed, retrying the same open form uploads the remaining files. If your sign-in has expired, sign in again. Underhood cannot save new records offline.

Both plans include a 30-day free trial once subscriptions launch. No card is required. Your trial starts on your first app or account visit after launch and acceptance of the current terms. After 30 days, choose whether to subscribe: Individual is $5/month; Family is $10/month. Saved records remain viewable and exportable if you do not subscribe. Complimentary accounts stay free. You may try either plan during your welcome trial without restarting its clock. A garage receives one welcome trial; prior live subscribers do not receive another. Trial dates appear in Account. Shared members use their garage owner’s access.