Auto Loan Rate Shopping

Show Buyers If Their Dealer Quote Costs Too Much

Give your users instant comparison across 4,300+ credit unions. Most dealer quotes are 1-3% higher than available credit union rates—show the savings instantly.

Last updated: January 28, 2026
Quick Answer

What is Auto Loan Rate Shopping with RateAPI?

Auto loan rate shopping means comparing a dealer's financing quote against credit union alternatives. RateAPI's decisions endpoint accepts a current offer (rate, APR, state, loan amount, term) and returns where it ranks against 4,300+ credit unions, plus estimated savings from better options. One API call replaces thousands of individual website visits. Credit unions typically offer rates 1-3% lower than dealer financing, saving buyers $1,000-$3,000+ over the loan term.

Buyers Can't Tell If Their Dealer Quote Is Competitive

A car buyer gets approved for dealer financing: 7.5% APR on a $30,000 loan. Is that good? They have no idea. The finance manager says it's "a great rate," but compared to what? The buyer has zero visibility into what rates are actually available in the market.

Meanwhile, credit unions in their area are offering 4.9%—but the buyer doesn't know these institutions exist, let alone what rates they offer. The information asymmetry costs them over $2,000 in unnecessary interest payments.

Your app can change this. With one API call, show users exactly where their dealer quote ranks against 4,300+ credit unions—and how much they could save by getting pre-approved before stepping into the dealership.

One API Call, Complete Market Intelligence

{}API Request
// Get auto loan recommendations for California
POST /v1/decisions
{
"decision_type": "financing",
"context": {
"geo": { "state": "CA" }
},
"product_request": {
"product_type": "auto_loan",
"amount": 30000,
"term_months": 60,
"intent": "purchase"
},
"current_offer": {
"rate": 7.5,
"apr": 7.65
}
}
{}API Response
{
"summary": {
"recommended_action": "shop_providers",
"confidence": 0.94,
"current_offer_rank": 742,
"total_providers_analyzed": 1156,
"estimated_savings": { "monthly": 42, "total": 2520 }
},
"actions": [{
"offers": [
{
"rank": 1,
"credit_union_name": "Navy Federal Credit Union",
"apr": 4.89,
"monthly_payment": 563,
"estimated_monthly_savings": 42
},
// ... more offers
]
}]
}

Built for Auto Loan Comparison

📈

Instant Dealer Quote Benchmarking

One API call returns ranked recommendations by true cost—APR, fees, and term length. Show buyers exactly where their dealer quote stands against the entire market.

🏢

4,300+ Credit Union Coverage

Access rates from institutions most buyers never discover. Credit unions often offer rates 1-3% below dealer financing.

💰

Transparent Savings Calculations

Every recommendation includes monthly payment and total interest savings. Buyers see real dollar impact, not abstract rate differences.

📅

Always Current Data

Daily updates via automated scraping. Every rate includes a timestamp so buyers know exactly when it was observed.

⚖️

True Cost Ranking

Lower advertised rates sometimes rank below higher ones when fees make them more expensive. We rank by what buyers will actually pay, not headline APR.

🛒

Multiple Term Lengths

Compare rates across 36, 48, 60, 72, and 84-month terms. Help buyers understand the trade-off between monthly payment and total interest paid.

Who Uses Auto Loan Comparison APIs

🚘

Car Buying Platforms

Show estimated monthly payments with multiple financing options next to vehicle listings.

💳

Personal Finance Apps

Help users optimize their auto loan by showing better refinancing opportunities.

🏢

Credit Unions

Demonstrate competitive advantage over dealer financing to attract new members.

Data You Can Trust

Zero Affiliate Relationships

Zero affiliate relationships means zero incentive to promote specific lenders. We rank purely by what's best for buyers.

🔗

Source URL Verification

Every rate links back to the original source page. Buyers can verify any data point themselves.

📊

Published Methodology

Our data collection and normalization process is fully documented. No black boxes.

🔒

No Lead Selling

We never sell user data or inquiries to lenders. Your users' privacy stays protected.

Try the API with cURL

Test the decisions endpoint directly with a simple cURL command. See how easy it is to compare dealer quotes against credit union alternatives.

$bash
# Compare a dealer quote in Texas
curl -X POST "https://api.rateapi.dev/v1/decisions" \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"decision_type": "financing",
"context": { "geo": { "state": "TX" } },
"product_request": {
"product_type": "auto_loan",
"intent": "purchase",
"amount": 25000,
"term_months": 60
},
"current_offer": { "rate": 6.9, "apr": 7.05 }
}'

Frequently Asked Questions

Common questions about auto loan rate shopping with RateAPI

How does the auto loan decisions endpoint work?

The decisions endpoint accepts a user's current auto loan offer (rate, APR, state, loan amount, term) and returns ranked alternatives from 4,300+ credit unions. It calculates where the current offer ranks, estimates potential savings, and provides actionable recommendations. One API call replaces manual comparison across thousands of lender websites.

What data do I need to compare auto loan rates?

To compare auto loan rates, you need the user's state (2-letter code), loan amount, loan intent (purchase, refinance, or lease buyout), term length in months, and optionally their current quoted rate and APR. The API uses this context to return relevant offers ranked by true cost, including monthly payment and total interest savings calculations.

How are auto loan savings calculated?

Savings are calculated by comparing the user's current offer against better alternatives. The API computes monthly payment differences and total interest savings over the loan term. For example, a 2% rate reduction on a $30,000 car loan over 60 months can save over $1,500 in total interest.

Why compare dealer financing with credit unions?

Credit unions often offer auto loan rates 1-3% lower than dealer financing. They're member-owned, non-profit institutions focused on member benefit rather than profit maximization. Most car buyers never compare dealer quotes against credit union options, leaving thousands of dollars on the table. RateAPI makes this comparison instant and comprehensive.

How fresh is the auto loan rate data?

Auto loan rate data is updated daily through automated scraping of 4,300+ credit union websites. Every rate includes a timestamp showing when it was last observed. This ensures users see current market conditions, not stale data from weeks or months ago.

Ready to Add Auto Loan Comparison to Your App?

Get your API key in seconds. Free tier includes 20 requests/month (or 50 with email). No signup form, no sales calls.