For dividend lovers, oil behemoths typically have been shelters during trying times.

But as the oil rout shows few signs of abating, this situation has changed. With about 5% stock gains this year, Chevron(CVX) - Get Report and ExxonMobil(XOM) - Get Report both offer extremely attractive 3.5% to 4.5% yields.

Should investors own both, then? Perhaps not.

Let's look at which stock really belongs in investors' dividend portfolios.

Starting with Chevron, Goldman Sachs raised its rating on the stock on Monday to "neutral" from "sell," following reports that the company is cutting its capital expenditure budget.

CVX data by YCharts

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In fact, management at the company is leaving no stone unturned to pay its $1.07 a share quarterly dividends. After two straight years of double-digit losses, which has happened only twice over the past four decades, it is difficult to stay unaffected.

The only assured return is the $4-and-change dividend for every Chevron share each year.

But ExxonMobil investors are also in the same boat in terms of consecutive years of stock price losses. ExxonMobil has talked about reducing fiscal 2016 capital expenditures by 25% to $23 billion and spending even less in 2017.

XOM data by YCharts

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However, what makes ExxonMobil a better and a safer dividend-paying investment than Chevron is its balance sheet strength.

With about $38 billion in total debt, Chevron's loans are more than twice trailing 12 months' earnings before interest, taxes, depreciation and amortization. However, ExxonMobil's similar debt pile offers a better ratio to EBITDA.

In addition, ExxonMobil is better than Chevron when it comes to paying reliable dividends.

First, though Chevron has a higher yield, its payout ratio of 241.8% is highly unsustainable to cover its dividends for a longer period. ExxonMobil's payout ratio is at about 72.8%, indicating a comfort factor.

Second, Chevron's $8.1 billion worth of dividends for the trailing 12 months are a huge strain on its $10 billion of negative free cash flow. ExxonMobil on a trailing-12-month basis is still free cash flow positive, even after paying $12 billion worth of dividends.

Finally, investors should pay attention to recent dividend hikes rather than look at dividend growth years. Although both Chevron and ExxonMobil have more than three decades of dividend growth history, last year showed that Chevron's dividends are probably running out of gas.

Compared with $4.21 in 2014, the shares generated $4.28 as dividends last year, representing paltry growth of 1.67%. ExxonMobil's shares offered dividend growth of 6.6% during the same time, going to $2.88 last year, from $2.70 in 2014.

It looks like that as time goes by in a difficult and low-priced oil business environment, Chevron will probably just about manage to maintain its dividends, rather than hiking them.

As it is, analysts don't see any huge movements in earnings growth for Chevron. ExxonMobil, on the other hand, is clearly moving into better earnings-per-share terrain, with a five-year run rate projected at 12.43%, compared with negative 14.41% in the previous five, underpinned by a big rebound in fiscal 2017.

Although 2017 is expected to show a big boost in Chevron's earnings per share as well, its forward five-year EPS growth run rate is still a negative nearly 24%, in line with its negative earnings trajectory of 26% over the previous five years.

The verdict: ExxonMobil is a bigger, stronger and safer dividend bet than Chevron.

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This article is commentary by an independent contributor. At the time of publication, the author held no positions in the stocks mentioned.